Chapter Text
Jack watched Sam bustle through the kitchen like a storm in soft slippers; quick, focused, and surrounded by the quiet urgency of someone trying to do five things at once. Sam moved from counter to sink to cabinet with practiced efficiency, muttering half-formed reminders to himself and adjusting the sleeves of his sweater like they were getting in the way of his thoughts. His scent filled the space as he stacked meal prep containers and various water bottles in his large arms. The scent he gave was warm, spiced with something just a little sharper when he was in motion. Jack found himself instinctively tracking it, and grounding himself in it. Omegas, he learned from Castiel, had a way of anchoring a room even when they were the ones stirring it up.
Jack continued to look on in morbid curiosity wondering just what exactly Sam was prepping for. He knew Sam and Dean didn’t have a case to go on, nor was company coming down in the bunker anytime soon. Jack couldn’t help but fidget in his seat a bit, the spiced scent making his skin feel clammy underneath his clothes.
“Uh… Sam?” Jack called hesitantly from the kitchen doorway.
“Just a minute.” Sam’s voice floated back as he breezed past Jack, arms full of supplies. He disappeared into the hallway without even glancing up.
Puzzled, Jack lingered a moment before finally deciding to get up and follow.
He found Sam crouched inside the linen closet, arms buried in piles of throws, blankets, and sheets. The omega was gathering nearly every soft thing he could reach, pulling it down with quiet determination.
“Sam?” Jack tried again, more curious now.
“Just a minute, Jack.” Sam repeated, distracted but not unkind. His focus didn’t waver as he hauled the overflowing bundle into his arms and turned down the hall, supplies hidden underneath.
Jack trailed behind, curiosity growing with every step. Instead of heading to the guest rooms, Sam veered toward the back of the bunker straight to the room Dean and Castiel had specifically told Jack not to enter. He figured it was filled with dangerous wards, or maybe even a weapons storage. Definitely not blanket territory and yet Sam walked right in, arms full of soft, scent-soaked fabric, as if it were the most natural thing in the world.
Jack paused, unsure. That definitely wasn’t weapons storage.
He was about to retreat back to the kitchen when a rush of footsteps made him turn; Dean was coming fast.
Jack had noticed for days now that Dean was also acting strange. Not just on edge, but frantic. Whatever Sam did, Dean seemed to mirror, only with more urgency. If Sam gathered blankets, Dean gathered supplies tenfold.
Now Jack watched as Dean barreled down the hallway, plastic bags swinging from both hands, each stuffed with things Jack couldn’t identify and couldn’t even guess. But he did notice that Dean never strayed far from Sam. Wherever the youngest Winchester went, Dean followed, hovering like a shadow with a mission.The bunker’s fridge was suddenly packed full and cases of water lined the pantry. Jack had seen Dean return from the store carrying what looked like medicine, or at least things that came from the same aisle.
To say Jack was confused would be an understatement.
He quietly turned away, deciding not to push for Sam’s attention again. Whatever this was, it felt important or urgent even, and Jack didn’t want to get in the way. He slipped back into the kitchen, where Castiel sat exactly as he last saw him: focused, quiet, and carefully constructing another sandwich with a precision he been proudly practicing.
”There you are,” Cas greeted. “I’ll be in charge of dinner tonight. Anything in particular you want to eat? I made you this sandwich.”
Jack shook his head but gratefully took the plate anyway. “Hey, why is everyone acting so weird?”
Cas cocked his head in confusion. “Weird?”
”Sam keeps taking things to that room down in the back. He took a lot of food and all the blankets. Dean’s been acting funny too. I know Dean was marking earlier, but why is Sam acting so odd?”
Castiel couldn’t help the small smile tugging at his lips. Jack’s ignorance was endearing, his innocence reminded the angel of his own early attempts to understand human behavior and the strange pull of instinct. Just like his angelic siblings, Castiel had never been assigned a designation. Castiel was no alpha or omega, nor even a beta. Celestial beings were powerful and ancient, they had no use for biological instincts. But years living among humans, watching and living with them, had taught him how deeply those instincts could run.
Castiel learned for instance, that marking was another form of nesting. It was a behavior unique to alphas. It could involve rearranging furniture, spreading their scent through chosen rooms, or even pacing in quiet, repetitive circles. It was all territorial, protective and in his opinion, primal.
Jack had started to notice it too. Dean would shift furniture in the bunker, hover in doorways, even pace through the kitchen each time Sam entered or left the room. It was subtle, but constant as if he was doing so unconsciously. Jack had picked up some of the same habits himself, though only in the privacy of his room. Alphas didn’t typically begin marking behaviors until they were older, but Jack being a Nephilim, had developed his designation months after he arrived in the Winchester’s lives. His instincts were slower to bloom, but they were there and growing everyday.
Castiel let out a quiet chuckle. “They are a bit frantic, aren’t they? Sam’s about to go into heat.”
Jack blinked, startled. “Heat?” Of all the answers, Jack definitely wasn’t expecting that.
In all his time living in the bunker, he couldn’t remember a single time Sam had gone into heat. He knew the basics: omegas cycled every three months normally, every six with suppressants. But somehow, he never pictured Sam in that state. Jack in that moment almost forgot Sam even had a cycle.
“I didn’t think that even happened to him.” Jack admitted.
Castiel didn’t answer right away. His gaze dropped to the table, hands stilling as the mood shifted.
“He’s been on suppressants for a long time.” He said finally, voice quiet. “Decades, Jack. Since he was young.”
Jack stayed silent, listening.
“They never stayed anywhere long. Sam and Dean were always on the move with no home, no pack, no stability. Suppressants were the only way to keep Sam from being vulnerable. From being… hunted.” He hesitated, something cold flickering behind his eyes.
“It kept him safe, right?”
“It kept him safe. But it hurt him too.”
Jack frowned. “Hurt him?”
Castiel nodded slowly. “Coming off them wasn’t easy. His body had to relearn how to function. The chemical damage alone-” He cut himself off, jaw tensing slightly. He glanced up at Jack, eyes somber. “That’s why Dean’s been following him everywhere and why he’s stockpiling supplies. He’s scared it’ll happen again.”
Jack’s chest ached at the thought. “Is Sam okay now?”
There was a beat of silence.
“Getting there,” Castiel said softly. “He’s finally getting used to having a natural heat. His body’s trying to remember what it’s supposed to do.”
Jack did recall the conversation he had with Dean some weeks ago, the older alpha becoming tense when Jack brought up the question of suppressants.
-
”Well I need to take them?” Jack had asked.
”No.” Dean answered with a snap. “That shit will fuck you up.”
-
“Are suppressants bad?” Jack asked, snapping out the quick flashback.
Cas shook his head. “They can be dangerous if taken too much. They can damage a normal cycle. Sam is finally in a place where he can settle, and with that is getting his cycle back on track and Dean can even allow himself to rut.”
Dean entered the kitchen just then, making a straight line for the fridge. “Are we talking about my private cycles now?” He asked, grabbing a beer without looking at anyone.
“Sorry.” Jack said quick and sheepishly.
Dean shrugged as he popped the cap. “Sam’s scent’s been driving me a little nuts lately. I’ve been marking more than I mean to. Makes sense you be curious.”
Castiel’s gaze lifted, concern flickering in his eyes. “Will we need to leave the bunker?”
The question sent a strange spike of anxiety through Jack. “Leave?” he echoed, turning to Dean. “I don’t want to leave. Do I have to?”
Dean glanced down at him. A grin tugged at the corner of his mouth as he walked over and ruffled Jack’s hair.
“Hopefully not,” he said. “I’ll let Cas decide that. As long as Sam stays in his nest, you should be fine.”
With that, Dean headed back out into the bunker, beer in hand, leaving Jack standing there feeling thoughtful, but filled with even more questions than before.
”Is Sam’s nest in the back room? The door that no one is allowed to open.”
Castiel nodded. “We can leave if the scent and influx of pheromones become too much. We can-“
”No!” Jacked interrupted, taken back by his own outburst. “I mean, no. I don’t want to be away from my room. My den.”
Cas gave him an assuring smile and nodded in understanding. “Alright, just make sure not to get too close to his nest. Try to stay clear of the hallway altogether. It should be fine.”
Jack couldn’t make sense of what he was feeling, he felt there was no logical reason for the knot forming in his stomach, or the way his heart picked up at the thought of Sam being in heat and being vulnerable, secluded, and just down the hall completely exposed to instinct.
What if Dean couldn’t protect him?
What if Castiel wasn’t around?
What if Sam needed something?
What if Sam needed him?
The thought struck deeper than Jack expected, sending a flush creeping up his neck and across his cheeks. His hands curled slightly on his lap, and he tried to push the thoughts away, but they kept circling like static in his mind. He couldn’t stomach the food on the plate in front of him.
“Jack?”
Castiel’s voice brought him back.
“Yeah,” he said quickly, blinking. “I’ll just… stay in my room. Or give them space! Whatever’s best.”
He stood from his chair and started down the hall toward his room, forcing himself not to look back in the direction of the youngest Winchester, but his eyes drifted anyway. They followed the curve of the hallway, toward the door at the end.
Sam’s nest room.
Jack slowed his steps. He didn’t know what he expected to see. Nothing was visible from here. But still something tugged at him like a strange, restless pull. He wanted to go and just to look, just to know he could. His fingers twitched at his side.
“You’ve been standing there for a while.”
Jack spun around, startled. Sam was standing just down the hallway, a plastic bag hanging loosely from his fingers.
“Sam!”
The omega gave him a small, tired smile. “You okay?”
“Yes! Yeah, I mean… I’m fine.” Jack’s stomach fluttered. His heart thudded so loudly in his ears, he was sure Sam could hear it. “I was just… looking for you, actually.”
“Me? Oh! That’s right, you were calling me earlier. I’m so sorry, Jack.”
“Yeah, I mean it’s fine! I just wanted to see what you were doing. Cas said you were, uh…” He trailed off, unsure how to finish that sentence without sounding weird.
Sam chuckled softly, stepping closer. “Yeah. I will be soon.” He said, finishing it for him.
Jack nodded quickly, eyes flicking toward the closed door at the end of the hall.
“I didn’t know you had a nest here.”
As soon as the words left his mouth, Jack regretted them. There was a flicker of something passed over Sam’s face, sadness, maybe even a memory.
“When we were on the road, I couldn’t exactly nest in every motel we stayed in.” Sam said with a soft, bitter laugh. “And it’s not like I could build one in the Impala. I’m protective of it, probably too much. Sometimes it feels like it’ll disappear if I’m not careful.” He finished with a small shrug.
Jack swallowed hard, nodding. He knew enough to understand that nesting wasn’t just habit- it was instinct. Intimate. Sacred. It was a place for an omega to feel safe. He figured years of suppressants might’ve dulled that instinct in Sam. That thought alone made something low and unfamiliar rumbled in Jack’s throat. He quickly cleared it before the Winchester could notice.
Sam tilted his head. “Do you want to see it?” He asked.
Jack blinked. “Y-your nest?” he stammered. “I can see it?”
Sam’s smile softened. “Yeah. If you want to.”
Before Jack could say anything else, Sam stepped beside him and gently laid a hand on his shoulder, guiding him forward. The warmth of his touch seeped through the fabric of Jack’s shirt, and suddenly it was all he could think about. The heat of Sam’s skin, the quiet rhythm of their footsteps echoing off the floor, the soft scent in the air growing stronger as they approached the room.
Jack’s heart raced. He knew what it meant to be invited into a nest.
It was sacred and incredibly private. Usually reserved for a bonded alpha or the omega’s pups. Even packmates were rarely given that kind of access unless the omega deeply trusted them. Sam was letting him in. The weight of that realization settled over Jack like a second skin. It stirred something deep inside him that was warm, protective, and just a little bit dizzying. He wondered if Castiel even had the privilege of seeing it.
The usual spiced scent of Sam thickened the closer they got to the door. It curled around Jack, warm and heavy, sinking into his skin and making his gums ache. He ran his tongue across his teeth, breath catching when he felt his incisors sharpening. His mouth filled with saliva, his body reacting before he understood why.
Inside the vaulted doorway was Sam’s nest.
As Jack stepped into the room, the first thing he noticed was the lighting that surrounded them. It was soft and dim, bathing everything in a rich amber glow giving an aura of warm, inviting, and almost romantic. The entire space was draped in fabric, from the ceiling down to the floor, layering the air with scent and comfort.
Sam’s scent. The scent of a brand new book and chai, of home.
In the center of the room, the floor dipped into a recessed hollow, sunken oversized bed almost like a pit. Pillows spilled out around the edges, blankets were meticulously chosen, folded, and layered as they created a soft wall around the nest’s perimeter along with a few shirts and articles of clothing he assumed was collected over the years. Was that a stuffed bear? Every inch of the space had been built, not just made.
“Sam,” Jack breathed, awe threading through his voice. “Your nest is beautiful.”
The youngest Winchester stepped past him, brushing Jack’s hair with a soft ruffle and beaming at the compliment.
“Thanks, Jack. Took some time. But if it’s where you go to feel safe… well, then you want it to be perfect.”
Sam slowly descended into the nest, hands moving with practiced care as he picked up pillows and rubbed them against the curve of his neck. Jack’s eyes locked onto the motion and onto the swollen scent glands just below Sam’s jaw he hasn’t noticed until now.
His heat was coming. Soon.
“Am I allowed to… be here?” Jack asked quietly, the real question lingering beneath it. Am I allowed to see you like this?
Sam gave a small chuckle. “Yes, Jack. I let you in. You only enter a nest if the omega opens it to you.” His tone was gentle, but firm showing it was a rule not a suggestion.
Jack nodded, he remembered that as one of the first lessons Castiel had taught him about biology, social etiquette, and what Dean called ‘the birds and the bees’. He took another step closer, soaking in the sight of the nest and of Sam preparing. It was all such a heavy reminder of what was coming in the next day, or maybe even in a few hours.
Something stirred deep in his chest.
Jack wanted to stay. He wanted to scent the blankets. He wanted to leave his mark, coat every corner of the room, and Sam, in his scent. The need to protect slammed into him so hard it made his knees weak. He didn’t understand why, but he wanted. His mouth started to water again. He could taste the sharp tang of alpha enzymes on his tongue. Before he could move, a rough voice cut through the haze.
“Sam.”
Jack flinched. He turned as his throat tightened, to see Dean standing in the doorway with his jaw tight and green eyes sharp.
“I’m just showing Jack,” Sam said not looking up, still focused on rubbing scent into soft cotton. “He’s never seen this room.”
Dean stepped into the room, his gaze flicking between the two of them. A low growl rumbled from his chest, it was an alpha warning another alpha to know their place. Jack stiffened at the grainy rasp. The sound hit something primal inside him, his own growl responded before he could stop it, low and rough, vibrating from his throat in instinctive challenge.
Both Winchesters froze.
“Jack?” Sam’s voice was gentle but cautious, concern settling on his face.
Dean stepped forward, putting himself between Jack and the nest, eyes narrowing. His fingers twitched at his sides and his posture was tense.
“What was that?” Dean asked quietly.
Jack realized what he just did.
“I-I’m sorry. I didn’t mean to- ” His breath caught, he felt like he was about to panic. Words stumbled over each other, thoughts tangled and impossible to pin down.
“Jack.” Dean started but didn’t get to finish.
“I don’t know why I did that. I didn’t mean to challenge you. You’re not- ” He swallowed hard. “You’re not a threat. I don’t want to fight.”
Jack’s scent, usually warm and earthy like sandalwood, now carried a sour note of distress. Sam rose carefully from the nest but staying behind Dean, cautious not to escalate the tension between the two alphas any further.
He kept his voice soft. “It’s okay, Jack. There’s a lot going on, you’re still learning.” He paused, then added, “Can you do something for me?”
Jack looked up quickly. “Anything.”
“Bring me something with your scent on it. Like a shirt, or something you had for a while. I want to add it to the nest.”
Jack’s eyes widened. “My scent?”
“I like having it nearby,” Sam said simply. “Yours and bring me something of Cas’.”
Dean scoffed. “Cas doesn’t have a scent.”
Sam reached forward and gave him a light punch to the back. “It’s still the thought, jerk. Let me be sentimental.”
”Bitch.” Dean muttered under his breath.
Jack nodded, already backing toward the door.
“I’ll bring something,” he said, then hesitated, eyes flicking to Dean. “I really am sorry.”
Dean shrugged, the tension starting to ease. He gave Jack a lopsided grin. “It’s alright, squirt. Just… go easy on the scenting next time.”
Jack gave a nervous smile and left the room, his thoughts still clouded, something restless humming just beneath his skin.
“Can I have your trench coat?”
Castiel’s eyes shot up to his brows. “Is there a reason why I’m shedding my clothes?”
Jack found Castiel in the garage, taking an old duffle out from the impala, a favor most likely asked of him from Dean.
”Sam needs it for his nest.”
Cas nodded his head in understanding. “I have something just for that. It will not be my coat, but I do have an old vest of mine from when I lived as a human. It should be in the foyer underneath the cabinet. I keep it there just for this.”
“I don’t understand why he wants it if there’s no scent.”
”It’s comfort, we are part of Sam’s pack and just the thought of the item close by in his nest during his most vulnerable time is good for his omega.”
Still, something about so many items with the foreign scent of others near Sam during said vulnerability left an angry taste in Jack’s mouth that he couldn’t explain. The only scent that needed to stay on Sam was his alone.
-
“Jack, enough with candy before you get a cavity.”
Sam placed his larger hand on Jack’s. They were making a milk run, or that’s what Dean called it. Castiel and the alpha were on a quick salt and burn while Sam decided to take Jack with him to the store since the bunker was getting low on their groceries and Jack took that moment to beeline right over to the candy aisle. Jack in that moment didn’t care to make the argument that he couldn’t get cavities or there was no such thing as not enough candy. Instead he could only focus on the warm large hand on top of his.
“You get one, just one. Got it? I swear you're going to eat this entire aisle when you come here.” Sam chuckled to himself, letting go of Jack's hand. The grazing of his fingertips leaving electricity across Jack’s own skin.
“I uh, I can uh, put it back.” Jack tried to get his thoughts back in motion, still reeling over the touch of the omega’s hand.
“No! No, Jack I’m sorry. I’m not mad I promise, just don’t want you eating so much of this junk.”
Jack decided at that moment he hated the solemn look in Sam’s face. It was of discomfort, something that he caused. He couldn’t let Sam think he was upset, he could never be upset at Sam. He quickly grabbed both of Sam’s hands in his.
“I’m not- I mean I don’t think you’re upset!” Jack rushed out the words. “There’s just so much to choose, I can’t decide.” He gave a nervous laugh, trying to brush off the discomfort he caused and the awkwardness he felt rushing up to his face.
Sam looked at Jack wide eyed, a small chuckle leaving out his own mouth. He looked down and their hands that Jack still had a death grip in. Jack also looked down, realizing what he was doing.
“Sorry! I’m sorry!”
Before he could let go, Sam pulled him in by their linked hands and wrapped his arms around Jack in a hug, one hand on top of his head pulling him to his chest while the other wrapped around his shoulders.
“Don’t ever apologize to me, Jack. You know, I’ve always seen you as my own pup. You can grab whatever and however much candy you want.”
The weight of Sam’s arms around him made time stop. He couldn’t even register that they were standing in the middle of aisle seven, surrounded by varieties of chocolate bars and discounted gummy worms. The fluorescents overhead didn’t seem so harsh, the clatter of carts, the hum of the freezer, it all faded in his ears. Warmth spread through his chest, slow and surprising like honey stirred into tea.
Jack became acutely aware of how Sam’s body fit against his own, how his omega scent- spiced, like a chai latte and that smell that comes from opening a new book- settled entirely around him. His once steady heartbeat took off in a rhythm he couldn’t reason with. Jack didn’t want to pull away, he let himself melt in the moment and in Sam’s arms. Not realizing this was the moment he wouldn’t be able to keep Sam off his mind indefinitely.
-
“Jack?”
The nephilim blinked out of his thoughts startled by the voice in front of him. Castiel stood there, brow furrowed, concern written across his usually impassive face.
“I think I’m going a bit haywire.” Jack admitted rubbing the back of his neck. “I growled at Dean… I didn’t mean to.”
Castiel’s eyes widened slightly. “Dean? Our Dean?”
Jack arched a brow. “Do we know another?”
The angel stepped in a little closer, pausing as if debating whether to put a hand on Jack’s shoulder. “Do you want to talk about it?”
Jack hesitated. The truth is, he was embarrassed.
Admitting that thinking about Sam made his body react in ways he couldn’t control made him feel broken, or worse, dangerous.
“I think it was me just being in his nest…” Jack said softly, voice trailing off like he wasn’t sure he should finish.
But Castiel understood instantly. Sam.
“You’ve never been this close to an omega preparing for heat before.” The angel said gently. “It’s normal to feel… overwhelmed. Even the instinct to lash out is common, I’ve seen it in others.”
Images flickered through Castiel’s mind of Dean. Tense and bristling, teeth bared at any stranger who got too close to Sam even outside of heat. Cas had always written it off as typical alpha behavior; protective, possessive, instinctual. Now even though Jack was still so new to his designation, he was also starting to mirror those same patterns.
“I just don’t want Dean to be mad at me.” Jack murmured with eyes dropping to the floor.
Castiel didn’t speak right away. Instead he reached forward and gently tilted Jack’s chin up so they were eye to eye.
“Dean isn’t mad,” he said firmly. “If he were, you would know. He’ll growl a little, maybe give you a correction. But you didn’t cross a line. You were affected, nothing more and that’s okay, Jack.”
Jack nodded slowly, taking that in. Castiel’s small nudge to his shoulder grounded him further.
“It’s time to head to your room.” Castiel continued, calm and measured. “You’ll need to stay there for the week. When you come out for anything, don’t linger near the hall. Give Sam his space.”
Jack gave a dramatic little eye roll, but nodded with each instruction. “I’m going now.”
“And if for any reason you want to leave here…” Castiel started, pausing to meet his eyes again. “Call for me.”
That sentence hit something in Jack like lightning.
The idea of leaving, of being too far from the nest and from Sam made his chest constrict. Panic welled up in his chest, immediate and visceral.
“No!” Jack blurted a little too loud. He caught himself quickly. “No, I don’t want to leave. I promise I’ll stay in my room.”
Castiel opened his mouth to respond but Jack was already gone, practically a blur down the hall. The angel watched the space where Jack had disappeared, arms folding across his chest, worry pooling quietly in his gut.
“Dean, please. I can handle the kitchen.”
Sam tried to move around the older Winchester to the door only to be blocked off once more, the back and forth between the two lasting the last half hour.
”I said no, your stubborn ass needs to stay right here. Whatever you need I will go or make Cas bring it over.”
“You’re herding me, you know that, right?”
Sam shot the accusation over his shoulder as he was moving around the room. He could feel Dean trailing just behind him watching, nudging, and gently directing him back toward the nest like Sam wouldn’t notice.
“I’m very aware,” Dean said flatly. “So make this easy on me. Your heat’s about to hit. You know it. I know it.”
Sam did know.
He could feel it in the throbbing ache low in his belly, in the way his scent was thickening in the air. He saw it in Dean too, the flare of his nostrils as he drank in Sam’s changing scent, the hard swallow in his throat as his Adam’s apple bobbed. The alpha was locked in, keyed up and ready. Sam’s slick pad was soaked and disgustingly uncomfortable now, he knew Dean was right.
His heat was close. Too close.
Sam felt it escalating the moment Jack left the hallway, almost like something in him had finally been given permission to unravel. The cramping in his stomach had started sharp and low. His nipples were tender, every pass of fabric over them like fire. And now slick was dripping steadily from him, a reminder of just how little time he had.
Dean had been circling him all day, keeping him close, herding him toward the nest without ever quite saying it until now.
“Fine. You win.” Sam threw his hands up, defeated.
The moment he surrendered, the cramps surged stronger and deeper. The dull ache rolled into a sharp contraction that bent him slightly at the waist. He hissed through his teeth, instinctively he began to pace around. It was the only thing that helped when the cramps got this bad. Pacing, moving, grounding himself in something rhythmic.
But Dean didn’t let him get far. He caught Sam’s arm mid-step and pulled him back gently but firmly, until Sam’s back was flush with his chest. Strong arms wrapped around his waist, circling him with warmth and quiet restraint.
Sam’s breath caught.
The weight of Dean’s touch, the heat of his body, the safety in it grounded him more than the pacing ever could.
”Dean.” Sam breathed out, voice barely more than a whisper.
The close contact, the way Dean’s chest pressed against his back, and the alpha scent wrapping around him like a weighted blanket was overwhelming his senses. Sam absolutely cherished his brother’s natural alpha scent, because Dean did not smell of your typical alpha. His scent was sweet, almost like an omega's. Alpha’s typically smelled bold and bitter, musky even. But Dean carried the scent of forest air after rain that reminded Sam of safety. It was an unmistakable blend of wintergreen and moss, and he took a deep breath so it could fill his lungs.
Sam wanted to drown in it.
“Let’s get you settled.” Dean murmured, voice dipping into that deep instinctual purr only an alpha could make. The low soothing noise was meant to calm and ground an omega.
The sound rumbled through Sam’s bones. His knees weakened, his breathing hitched, and he could already feel slick starting to pool, threatening to drip down his thighs.
”Are you close?” He could barely get out.
”Hm?”
”To your rut?” Sam asked quietly, as if anyone around could hear what they say in the privacy of this room.
Sam felt Dean shake his head behind him firmly and certain.
“My rut won’t start until we’re deep into your heat.”
His voice was controlled, but there was a thread of tension underneath, something tightly wound. Dean always held back until Sam was fully under. It was instinct that his alpha wouldn’t let him lose control until Sam was safe, until his nest was built, his body ready, and his omega instincts surrendered completely. Only then would Dean allow himself to rut.
Sam chuckled softly, trying to lighten the moment. “Worried you might hurt me?”
He turned in Dean’s arms, wrapping his own around the shorter man, pressing their foreheads together. The warmth of Dean’s skin was grounding, the familiar weight of him comforting even as the fire in Sam’s belly began to grow.
“You can let go, you know,” Sam whispered. “I trust you. I want us to start together.”
But the moment those words left his mouth, Dean growled a rough and carnal sound.
A warning.
Sam flinched slightly, instinct pulling him back a step. His omega understood that sound.
“You ask me this every time.” Dean bit out, voice edged with frustration. “The answer is no. Don’t push it, Sam.”
There was something raw in the way he said it. He wasn’t just annoyed, Dean was scared. Scared of being too far gone to protect his brother, of hurting Sam when he needed care the most. Sam could recall the number of times he became sick from his heat while his body regulated off suppressants. He knew it wasn’t easy for Dean and that was Dean’s final boundary. Seeing his alpha so protective hit Sam’s instincts like a switch.
His body flushed with heat, skin prickling. His scent shifted in the space between them, suddenly richer, headier. The first waves of fever crept in beneath his skin, tight and aching. The cramps returned with a vengeance, deep, rolling, pulling across his stomach like his body was curling in on itself. Sam bit his lip trying to stifle his groan.
It hurt.
The pain was coming more than usual, more than he remembered. Suppressants had dulled everything for so long, but now his body was re-learning how to feel. Every contraction, every nerve, every instinct was raw and alive.
”Your heat is starting.” Dean said gently, officially pushing Sam down into his sunken nest. Sam has to stifle a whimper when Dean leaned down and swiped his tongue across his red bitten lips, wanting to gain access to his mouth.
”Alpha.” Sam gasps out, letting Dean take advantage of his open mouth and getting swept away by the slurping of their saliva.
Sam turned his head away to catch his breath, his arms wrapping around the alpha above him. The alpha enticed Sam in for a chaste kiss, before planting a kiss to Sam’s jaw and moving up to his ear. “You like that, omega?” His voice deep.
”Yes… please, yes.” Sam whimpered, tilting his head to the side.
”Hey, look at me puppy.” Dean encouraged, taking Sam’s chin between his thumb and index finger. “Want to see my baby boy.” He stroked his thumb under Sam’s bottom lip. Dean leaned back to take a look at his flushed face omega, and saw the hazel eyes he loved were gone and replaced with dilated black pupils.
Sam was officially in his heat.
“Let’s get these clothes off you, puppy. Let me see how beautiful you are.”
Dean stripped out Sam, taking the moment to admire him and breathe in the rich scent of his brother. The scent he came to love, to mate, the scent that became home. The alpha gently turned Sam over to get him in position, knowing he would need to be knotted soon.
Jack wasn’t sulking.
He definitely wasn’t pouting.
But he was extremely upset.
The young alpha had been there for hours now lying still on Sam’s stripped bed, face pressed deep into the mattress, trying to breathe in what little traces of pre-heat scent still lingered. The room felt stale and quiet in that timeless bunker way with no natural light, and no indication of how long he really was there except for the ache in his limbs and the way the lamp buzzed faintly beside him.
The scent had dulled over time, almost gone now, but he stayed anyway. Jack hadn’t moved much, just shifted positions occasionally and rolled over once, then he went right back again to press closer to the mattress. Sam’s scent had been stronger before. He caught it immediately when he first walked in. The soft spiced musk tinged with something richer but it had faded and was pulled away with the sheets and the blankets along with Sam himself.
Down the hall. Nesting. In heat. With another alpha.
Jack’s fingers curled into the mattress, his stomach twisted again. A low growl crawled up the back of his throat, and he clapped a hand over his mouth to stop it from slipping out.
The idea of another alpha even if it was Dean- being close to his Sam, touching him, scenting him, claiming him…
Jack shot upright, heart pounding, and began to pace.
My Sam.
The thought came out of nowhere. But it hit like lightning.
“My Sam?”
Sam wasn’t his. He never had been. Sam belonged to Dean, they were bonded, tied together in a way Jack couldn’t even begin to understand. Dean had been there through every cycle, every heat, every low and high. They weren't just brothers, they were mates. Jack didn’t have a claim. Yet he couldn’t forget the way Sam’s rough hands had cupped his face. The way he rested his cheek on Jack’s hair when they hugged. The soft, fond smile when he added Jack’s shirt to the nest, when he said he wanted Jack’s scent close.
He couldn’t stop thinking about Sam.
Jack shook his head, forcing himself to push the thoughts down, and begrudgingly turned to make his way back toward his room. His steps were reluctant but echoing through the long metal hallway. As he passed through the library, his eyes drifted not forward to his own room, but instead toward the opposite hall that led to Sam’s nesting room.
His gaze stared down the corridor. Jack knew he shouldn’t, he promised Castiel and promised himself. But at that moment he couldn’t think of any harm in just getting a little closer. He wanted to walk down just enough to catch a trace of scent in the air, or something to carry back with him in the empty silence of his own room. Jack stayed paused at the intersection of the two halls, standing alone between decision and desire.
Hall A is the path back to his own room which was safe and expected.
Hall B is ending in a bolted door that now calls to every nerve in his body.
“Just a peek. Then I’ll go back.” Jack reasoned with himself weakly.
He inched down the forbidden hallway, inhaling with every cautious step, searching for even the faintest note of Sam’s scent in the still air. And when he finally reached the door, he hesitated as his heart was pounding, muscles tense, instincts crawling just under his skin.
He pressed his ear to the door but there was nothing, just silence. Jack glanced over his shoulder searching for any sign of Castiel and listening for any footsteps or any witnesses.
“If it’s locked, I’ll leave.” Jack told himself.
His hand closed around the handle. The latch clicked, and the door cracked open just a sliver, but just enough.
The scent hit him like a tidal wave. Heat. Pheromones. Sam. The scent was rich and potent, it rushed past the threshold and knocked the breath from his lungs. Jack reeled back a step, staggering as his mouth filled with thick saliva suddenly. It spilled down his chin before he could swallow, his throat working to contain the surge of alpha enzymes.
His incisors lengthened, breaking past the gumline with a dull throb. A low and involuntary growl began curling up from his chest and he had to clench his jaw to stop it. His hands were shaking but the image that greeted him as he looked inside shook him to the core.
Sam was pinned, tear streaked face pressed into the bed with Dean behind him holding a death grip on his hips. The sound of Sam panting would forever be burned into Jack’s memory. He could see from the angle he was at where Dean pressed right behind him, his back slightly hiding the view of where he was inside Sam. Jack just couldn’t look away as the other alpha pulled out halfway only to slam back in, electing a gasp straight from Sam’s mouth.
”There! Right there-!” Sam moaned shamelessly, Jack could see his hands desperately gripping the sheets and the nephilim wished in that moment it was him.
He wanted to know what it would feel like to be inside Sam, fucking him into overstimulation as his walls gripped him tight. Jack slid a hand down to cup over himself, his cock now hard and leaking inside his own sweatpants.
”Here?” Dean teased, thrusting at a shallow pace wanting Sam to whine and beg him to go faster. “Tell me what you want, puppy. I’ll give you whatever you want, tell me how you want me to fuck you baby boy.”
Drool begins running out Sam’s mouth. Everything felt like it was too much, from the tip of the cock inside him nudging to the entrance of his cervix to the sensation of the fabric beneath rubbing on his already raw and sore nipples whenever Dean fucks into him. “A-Alpha…” Sam was nearly delirious.
Jack was officially rubbing himself, timing each jerk of his own cock with each thrust of Dean’s hips into Sam. Jack could see where the omega was stretched out around his alpha’s girth. He could see Sam’s ass bounce with every slam into him. “Fuck!” Jack whispered out, throwing his head back and getting lost in his own pleasure drowning in the sound of Sam getting fucked.
“Nnn-haha-aahnn-“ Sam was keening, the omega noise came out as a half-broken sob, tearing out of him unrelenting and trembling.
Dean fucked in a way that was obvious he was claiming Sam. Like he wanted the omega under him to feel every thrust, every touch, and with the full intention that Sam knows only his older brother could touch him this way. That his body belongs to Dean and no one else.
”Fuck, Sammy.” Dean moaned out, his nails leaving crescents in Sam's skin, while his hips grind into his brother’s hole. “You feel so god, fuck- you feel so good. So hot, so damn tight. My good puppy, my perfect omega.”
”Knot me, I need to feel your knot… please.” Sam begged, hips pushing and clenching around Dean’s girth in a way the elder couldn’t help but let out a hiss.
”Shhh, baby. I’ll give you a knot soon.” Dean cooed at Sam. “Just take it. You’re doing so good.”
Jack could tell Sam was close, and by the way Dean grabbed the back of Sam’s neck in a hold he knew the other alpha was too. “Don’t wanna knot you yet, fuck Sammy. Need to feel you clenching on me a lil’ more. Can you do that for me, puppy?”
”No! Aahh- need your knot. De’ please, knot me! Alpha, please!” Sam’s body was jerking, trying to fuck himself back against Dean. He was so close, this feeling pooling in his stomach.
Dean kept the firm grip on the back of Sam’s neck, he eased the grip he had on Sam’s hip with his other hand; rubbing soothing circles with the pad of his thumb. “Shhh, easy baby boy. Just a bit longer, take it just a lil’ longer. I’ll knot you soon puppy.”
”Gonna cum! De’, go-gonna cum, so close…” Sam gasped out with each thrust, he pillowed his arms and laid down on them, trying to bite back the moans pushing out of him with each of Dean’s thrust with his ass still in the air.
”Go ahead, cum for me Sammy. I’ll knot you soon, but right now just take it. Good fucking boy, just like this. Fucking take it.” Dean threw his own head back, getting lost in the feeling of Sam.
That sets the nail in the coffin, Sam’s orgasm rips through him and he comes hard.
Jack could see the gush of slick sliding down the omega’s thighs. He had to place a fist his mouth, biting down on his knuckle to keep from giving himself away.
”Good boy, good fucking puppy.” Dean is still fucking into Sam at a shallow pace, the body quivering beneath him riding the aftershocks of the orgasm.
“No more, alpha… please…” Sam choked out with obvious difficulty.
”Shhh Sammy, you’re almost there. You need to take it a little more before I knot you.”
Sam whined pathetically. “I can’t.” The breathless feeling washed over him, he tried to adjust the pace but Dean wouldn’t let up. The overstimulation made it so the drag of his alpha’s cock against his walls was nearly painful.
”Omega.” The alpha growl caused Sam to flinch. “You need to release as much as you can before my knot. I don’t want you to get sick again.”
Dean lets go of the back of Sam’s neck, sitting straight up with Sam’s hips in both hands as he lifts his ass up entirely. Jack could see slick running down the back and sides of Sam’s thighs, down his belly and dripping straight onto the fabric below. He wanted to crawl forward on his hands and knees for a better smell.
Fuck, did he just want a taste.
Jack was biting down hard on his lip to stop his moaning from being heard as his hand slid up and down his length. Pre-cum slicked up his erection, but he wished it were Sam’s slick instead. He was close to his own release.
Almost violently, Dean began to piston into Sam at a brutal pace. Sam’s entire body jerks with his alpha’s movements. “Fuck! Dean! Alphaaa-nnng-haaah!” Sam was trying to pull himself away from his alpha’s grip. It was too much. It feels too good. He couldn’t take anymore, he felt he was going to faint right into the cushions below.
”So good Sammy, my good omega. So damn wet for me.”
Dean fucks into him like an animal, his pace merciless against his already red ass cheeks. The sweet wintergreen scent turns into a dark bitter tinge with a likeness to the whiskey the alpha drinks on certain days. He leaned down to lick over the bite mark on the back of Sam’s neck. His cock slamming into Sam’s hole causing a squelching noise to echo throughout the room, the obscene sound was all it took for Jack to feel his own orgasm wash over him.
”Shit!” Jack hissed out, riding out his own ecstasy but still watching Dean pound down into Sam. He tried to do what he could to clean himself as he wiped off his hand on the side of his pants.
Jack looked back into the slit of the door, he thought of himself in Dean’s place and wondered how he could make it work. Sam was such a large omega, could Jack be big enough to take him from behind like Dean could? Would it be easier on Sam if the omega were to ride him? The thought of Sam on his lap, slowly lowering himself on his cock was almost enough to make Jack hard all over again. He watched as Dean continued to nose the mark on the back of Sam’s neck, it was bright red as if it was just bitten recently. Jack ran his tongue back over his incisors, picturing what it felt like to have the skin of Sam’s neck trapped between his teeth. Jack’s alpha crooned, believing Sam would look beautiful with his mark.
Out of nowhere, a hand seized the front of Jack’s hoodie and yanked him sideways.
He stumbled, off-balance, the hallway vanishing in a blur then replaced by the four familiar walls of his room. He barely had time to catch his breath before he was face-to-face with an absolutely livid Castiel.
“I-I can…” Jack stammered, words tripping over the panic in his throat. “I was just…”
There was no excuse. Not one that could justify what he just done.
“What the hell were you thinking?!” Castiel snapped, voice sharper than Jack had ever heard it. Jack recoiled with his heart pounding. He never seen the angel so angry like this, especially not at him.
“I was going to get water, I didn’t mean to…” Jack trailed off, gaze dropping to Castiel’s polished shoes with his throat tightening.
“They’re mating, Jack.” Castiel’s hand gripped his shoulder in a firm and unyielding hold only a nephilim could tolerate, forcing Jack to meet his eyes. “You should never have been near that room! Near them.”
Jack’s breath hitched and his eyes began to sting. “I’m sorry.” He whispered, his voice cracking as tears welled up and spilled over.
But Castiel was already moving, kneeling down and yanking a forest green duffle from beneath the bed. He shoved it into straight Jack’s arms.
“We’re leaving.”
Jack froze. “What? No! I don’t want to leave. I’ll stay in here, I swear! I won’t even go near the hall- ”
“Jack… no.” Castiel’s tone softened just a fraction. He picked the bag up again when Jack let it fall, pressing it into his chest more gently this time. “It’s not safe for you. For any of you. We’ll come back when Sam’s heat is over.”
Jack’s head shook violently, tears now spilling freely. “Please, Cas please, I don’t want to go!”
“If Dean had seen you at that door, he would have tried to kill you.” Castiel’s voice dropped, quiet and firm. “Not because he wanted to, because his alpha instincts would’ve taken over. He wouldn’t have had a choice.”
Jack looked stricken.
“Sam is in the middle of his heat, Jack. You think another alpha’s scent near him would’ve gone unnoticed?” Castiel added. “You’re lucky I found you first.”
Jack looked away, his shoulders hunched not just from feeling guilty, but embarrassment. He hadn’t meant to stay near the door that long, he most definitely didn’t plan to get off on watching them. But once he caught Sam’s scent, it was like his feet rooted to the floor.
“I was just peeking…” He mumbled. “I smelled him, and my body just… moved on its own.”
Castiel’s expression remained firm. “You’re not in control right now, Jack. We’ll come back when it’s over. But I think it would be wise to stay away a little longer. Give the bunker time to clear.”
Jack’s bag dropped from his arms again with a thud, frustration breaking through the fog of shame. His eyes flashed a familiar white glow as he bared his teeth.
“No! I didn’t even want to leave and now I have to stay gone? No, Cas!”
“I didn’t say stay gone.” Castiel replied evenly. “I said a few extra days. For your sake.”
“I don’t want to!” Jack snapped. “I don’t want to be away from him-” He froze, chest heaving, words catching in his throat. “I mean… I just don’t want to be far from the pack.”
But Castiel didn’t buy the correction. He stepped forward and Jack instinctively stepped back. The angel studied him closely. He combed through the nephilim’s expression of embarrassment and confusion because Castiel knew it all too well.
“Jack…” He said softly. “Did you imprint on Sam?”
The guilt hit Jack’s face before the words even did.
“I-I don’t know,” he murmured. “Maybe.”
But Castiel already knew. He thought back on the odd behaviors, Jack shadowing Sam through the halls, the shirt he saw him rubbing hard against his scent glands before handing it off for the nest. The growling. The possessiveness. The scent of arousal that had filled the air when Cas pulled him from the hall.
At first, the angel assumed it was Jack’s rut approaching but he saw now this was more.
“You’ve imprinted on him,” Castiel said gently. “You’ve formed a bond. Whether you meant to or not… you’re seeing Sam as your omega now.”
Jack’s cheeks flared with heat. He looked away, voice small. “I thought it was just a crush…”
“He belongs to Dean.” Castiel said bluntly.
The reaction was immediate, a low growl ripped from Jack’s chest sounding like a territorial warning and just as fast, it was gone. Jack slapped a hand over his mouth, horror in his eyes.
“I’m sorry! I-I didn’t mean.”
Castiel didn’t flinch from the reaction. “It’s more than a crush now. And being exposed to Sam’s heat only intensified it. We’ll talk more later but right now, you’re leaving. That’s final.” He paused, eyes softening just slightly. “I’m sorry, truly I am. You have two minutes, Jack. Or I’ll make you leave.”
With a sharp flutter of wings, Castiel vanished and the room went still.
Jack stood frozen for a moment, his heart pounding with a mix of shame and anger. But not at Castiel, the angel was right. Still it didn’t make the truth hurt any less. He didn’t mean for his feelings to go this far. Jack wasn’t delusional, he knew what Sam and Dean were to each other but still the thought tugged at him.
I could be good for Sam. I could protect him. I can take care of him. I could do it right.
He picked up his bag with a sudden resolve. If he was going to be forced to have time away, then he would use it. He had a lot of research to do. Jack could learn what it took to be a good alpha, one that Sam might choose.