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Senku didn’t waste much time thinking about the societal politics of alphas, betas, and omegas. It wasn’t that he looked down on it - as an alpha and a scientist he acknowledged that certain biological imperatives had developed over thousands of generations of evolution and therefore had at least some reason for existing. He just found it irrelevant to his day-to-day life - chemistry didn’t care about scent hierarchies and physics wasn’t affected by estrus cycles.
Post petrification he gave just enough thought to get a rough estimate of when certain people would hit their cycles for resource planning, but beyond that gave little care to what he considered to be the interpersonal bullshit that went along with dynamic politics. That was Gen’s problem to deal with.
Which made it particularly annoying when it was Gen’s weird behavior during his cycles that he found himself having to put up with.
The first time Gen had slunk into the lab with pupils blown wide and a veritable cloud of heat pheromones clinging to him, Senku had assumed he was prowling for a cola and tried to shoo him away.
“Get off,” he’d grumbled, trying to peel slender arms from around his waist as Gen draped himself over his back like an overly affectionate cat.
“You’re warm,” Gen had purred, nuzzling into his shoulder, “and you smell nice.”
“You’re in heat, everyone smells nice to you,” he wriggled, hoping to dislodge him. “Ukyo’s an omega, too, go bug him,”
Rolling his eyes at Gen’s petulant whine and the way he cuddled closer, Senku thought back to his high school sex ed classes. He’d paid just enough attention to get the basics, more focused on alphas for obvious self serving reasons, but could vaguely recall a few bullet points on how omegas in heat behaved and why - interspersed with the hooting and snickering of the other alphas in class.
Hormonal fluctuations leading to mood swings and an instinctual urge to increase oxytocin, serotonin, and dopamine. An evolutionary urge to confirm safety and security, most unmated omegas sought physical closeness with trusted friends or family members of any designation - something Senku was somewhat familiar with as Yuzuriha had deemed him a safe outlet for her weird need to snuggle during her cycle.
While she naturally gravitated more towards Taiju or her omega friends, it wasn’t odd for her to sometimes just press up against his side or back for a moment or two or hold onto his arm when the Big Oaf wasn’t around. At first he’d been worried about the implication of the behavior and Taiju’s reaction but quickly realized the platonic nature and let it be - if anything, the consistent exposure to Yuzuriha’s scent helped regulate his own system without him having to really do anything himself.
Gen had seemingly made the same determination, though Senku couldn’t help but wonder what had inspired the change in behavior. Gen had gone through three cycles since joining the village and had never sought him out before - in fact Senku couldn’t recall Gen showing really any of the stereotypical omega behavior during his previous cycles. Just a subtle change to his scent and a bit more lethargy than usual, certainly not hanging all over anyone.
Senku was about to ask about the change, attempting to disentangle himself from the omega’s clinging only for Gen to bite him.
“Ow, what the fuck was that?”
It hadn't really hurt, the leather of Senku's sleeve taking most of the pressure off his bicep to the point that he doubted there was even an indent of teeth in his skin, but it was the principle of the thing. Especially in how Gen acted like he hadn’t done anything, humming pleasantly as he nuzzled against the collar of Senku’s coat.
After a few more failed attempts, Senku gave up on trying to argue. His best supposition was the change in locale from Ishigami Village to Roppongi Hills had sent Gen’s instincts haywire and there was no point in wasting energy to fight a losing battle. If Gen was anything like Yuzuriha, he’d wander off soon enough in search of some other source of creature comfort - some sort of sweet food or a cozy blanket to wrap himself in.
Except he didn’t and Senku found himself with a particularly cuddly Gen-shaped shadow for the next few days.
Senku absently wondered if the difference in behavior was because Gen was a male omega, or if it was just a matter of personalities, but like with most dynamic considerations he quickly shrugged it off as not worth dedicating much thought to. As far as he was concerned, Yuzuriha had been the only omega he'd ever interacted with consistently as more than an acquaintance and it had been short-sighted for him to have expected a one-to-one comparison. Yuzuriha had several outlets during her heats, with Taiju being her obvious (to everyone except the oaf of an alpha) preference whereas Gen tended to keep most people at arm's length giving him fewer options.
So when the behavior repeated three months later Senku gave a perfunctory argument before resigning himself to his fate of having Gen coiled around him like a boa constrictor for the duration of his heat.
They hadn’t ever talked about it directly - one day Gen was clinging to him and following him everywhere and the next day he was back to normal as if nothing had happened. He hadn’t seemed embarrassed or concerned about his behavior and beyond a few teasing comments from Chrome and a few others Senku wasn’t particularly bothered either. On paper it was fairly standard co-habitating behavior - Senku was the person Gen spent most of his time around and who he shared a living space with. It made sense that he didn’t see Senku as a threat despite being an unmated alpha, instincts acknowledging him and any of their shared spaces as safe during a vulnerable time.
The scenting was new, but unobtrusive enough, and Gen made sure not to get in the way of Senku’s work during the day, letting him go when Senku actually needed him to and keeping physical contact rather tame. Half the time, the omega seemed perfectly content just sitting or napping in the room with him without needing to touch him at all, though Senku had learned rather quickly that trying to assign Gen a task during that time would result in a Mentalist shaped barnacle for the next hour at minimum.
It wasn’t anything Senku would have actively sought out, but considering the worst of it seemed to be acting as a human teddy bear and having to share his bedroll for a few days every three months he let it be. He chalked it up to “omega stuff” and Gen just being weird as usual.
Which was probably why he didn’t give too much thought when, leading up to and during Gen’s next cycle, his behavior started to shift.
He didn’t bat an eye when Gen’s scent started to sharpen any time another alpha wandered too close or how his expression soured the moment one entered the lab, shrugging it off as an unmated omega being unwelcome towards strange alphas. Though when he hissed like a feral cat the time Ryusui had poked his head in to discuss schematics, glaring at the other alpha over Senku’s shoulder, he’d been a little confused - but knowing Ryusui and his habit of speaking without thinking, it wasn't hard to believe that he'd said something to piss Gen off.
He’d raised a brow at the way Gen’s already firm hold on him tightened further, draping over him like a particularly heavy blanket and scent thickening the moment Ukyo or one of the sparkling sisters walked by. Different than when an alpha came near but somehow more defensive - but eventually he just started adjusting his position to bear the weight more comfortably while he waited for the other omegas to pass by.
The morning Gen physically shoved Chrome out of the observatory, heedless to how the brunette almost went tumbling down the ladder was concerning - but when he chucked his bag out after him and began scenting Senku rather aggressively, he figured it was just an omega being territorial about their den - perfectly normal behavior.
On face value, none of it was particularly unheard of - practically textbook instinctual defense mechanisms for an omega in heat. But Senku couldn’t recall ever seeing one quite as… snappish as Gen was.
Though, again, Yuzuriha was the omega he was most familiar with and he couldn’t really picture her being angry let alone aggressive. When no one else mentioned anything off about the behavior, Senku decided to just shrug and roll with it.
If no one else was worried or found it strange, no reason for him to.
It came to a head one afternoon when the sounds of a scuffle burst through the ship yard. Pained yelps and an angry shout had Senku looked up at Chrome and Ryusui in concern, and without a word the three alphas burst into action.
They’d expected to find two alphas tussling, tempers flaring to the point of exchanging blows - it had been a much more common occurrence when Tsukasa’s camp had first been introduced but still popped up from time to time. They definitely hadn’t expected to find Gen pinning one of the large, hulking alphas from Tsukasa’s camp to the ground, face in the dirt and arm twisted behind his back in an obviously painful angle.
Gen’s teeth were bared, eyes narrowed to slits, growling low in his throat. His scent was thick with heat pheromones, acrid with anger that stung the back of Senku’s throat and by the way Ryusui and Chrome were flinching they could smell it too.
“What the fuck? I didn’t do anything!” The alpha shouted, trying to wriggle away and grunting as the movement pulled at his shoulder.
Gen snarled, leaning more of weight onto him. His head raised as Ryusui approached, glowering at him and snapping at the hand he’d reached out.
“Fuck off.”
Senku blinked, not only at the sound of Gen cursing but at how cold and dangerous his tone was. There was a very clear threat being made and it seemed that the alpha on the ground hadn’t heeded it.
“Get him offa me!” the alpha thrashed again, grunting when Gen pinned him more firmly, nails digging into his forearm.
Chrome nudged Senku forward, “That’s all you, man,”
“Huh? What am I gonna be able to do?”
“He won't freak out on you,” Chrome shrugged, head jerking in Gen’s direction. “You saw what happened to Ryusui, either of us try we'll end up like Kota, or worse. I didn’t wake up planning to lose an arm today.”
Rolling his eyes, Senku gave Chrome a withering look and sighed, taking a step forward. “Gen, let him up.”
“He tried to scent me,” Gen hissed, grip on Kota’s arm tightening and the sound of bone grinding on bone audible even at the distance Senku still was.
Ryusui inhaled sharply, “He did what?”
Senku scowled, Kota deflating under his gaze. While it was normal, if not expected, for an omega to scent others while in their heat it was completely unacceptable for an alpha to return the gesture without consent - one was an act spurred by safety and security, the other came with the implication of dominance and ownership.
“I was just askin’ him if he needed some company! Not my fault he’s out smelling like tha- fuck!” Gen jerked his arm and Kota writhed in pain. “Mother- I barely even touched you!”
“You stink,” Gen rumbled sourly. “I told you to go away.”
“I thought you were playin’ hard to get! You’re obviously not getting dicked down enough if you’re this high str-“
Kota’s voice broke into a pained scream and Ryusui folded his arms over his chest disapprovingly, making no move to intervene. “I say we just let Gen deal with him,”
“I still don’t understand how he’s dealing with him now,” Chrome was eyeing the pair in confusion. Kota easily had a foot of height and several kilos of muscle on the delicate omega, and yet somehow Gen had managed to subdue him with ease.
“I didn’t mean anything by it, I was just messing around!” Kota insisted, wincing as his wriggling pulled against his shoulder painfully. “Take the fuckin’ compliment!”
Senku finally stepped forward, noting absently that Chrome was right and Gen barely reacted to his approach. With a huff, he crouched down to be eye level with the irritated omega, “Let him go before you break something I have to fix.”
For a moment he wasn’t sure if Gen had heard him, pupils still pinpricks of threat, lips curled over his teeth. His scent had soured even further at Kota’s continued complaints, but the moment the omega’s gaze flicked to him the acrid odor dissipated, replaced with the familiar brightness of plum wine and jasmine.
The snarl faded, tension in his shoulders melting away - so abrupt as to be almost startling. His grip loosened and Kota jerked his arm free, scrambling out from under him.
“Fucking crazy ass omega,” he panted, stumbling to his feet and clutching at his shoulder.
Senku gave him an unimpressed look, seemingly unfazed by the way Gen had latched onto him instead, tucked against his side comfortably. “Considering you tried to scent him without his consent, you’re lucky that’s all he did to you. Didn’t you pay attention in school when they went over heats?”
“Shouldn’t be out here smellin’ like-“ Kota’s mouth snapped shut when the soft purr Gen was rumbling with deepened into a threatening growl. Cowed for the moment, he muttered out an apology, cringing when Ryusui clapped him painfully on his injured shoulder with a smile that was all teeth.
“Don’t you worry, Senku, Kota and I will have a nice long chat about proper behavior while we get this arm looked at, won’t we?”
Kota looked like he was going to argue but wisely kept his mouth shut, letting Ryusui lead him away.
“Are we going to address how Gen took down a guy twice his size, or…?” Chrome watched as Senku pushed to his feet, struggling to maintain his balance with Gen hanging off him like a tenacious burr.
“Adrenaline can do that,” Senku shrugged dismissively. “Everyone knows not to fuck with an omega in heat without permission,”
“Yeah, but Gen practically ripped his arm off…” Chrome shook his head slowly. He sniffed, nose wrinkling as he lifted a hand to it, “Fuck, Kota really pissed him off, how can you stand being so close to that smell? It’s like… burning hair, ugh…”
As if on cue, Gen nuzzled into the space between Senku’s neck and shoulder with a soft rumble that felt more intentional than instinctual. Senku rolled his eyes, adjusting his stance as Gen crowded even closer, glowering at Chrome over his shoulder. It was a silent, unmistakable threat to the only other alpha left in the vicinity.
Back off.
“You’re being ridiculous,” Senku muttered, at Gen or the situation he wasn’t quite sure.
Gen made a soft, satisfied noise and Senku took a few sniffs as the omega nuzzled into his arm. He detected nothing but his usual scent tinged with the warm notes of heat - the bitter scent of anger had dissipated quickly as far as he could tell. If he really focused he picked up something slightly off, but while he couldn’t quite put his finger on what it was he wouldn’t call it a bad smell.
“Smells way less pissed off than he did when we got here to me, he’s just clingy.”
As if to prove his point, Gen chose that moment to bite down on his shoulder.
He stiffened, not because it hurt or because it startled him, but because the nuzzle that followed was warm and deliberate and had no business sending a jolt of something suspiciously close to… something down his spine.
And of course Chrome had seen it.
“Just clingy, huh?”
Senku swallowed, clearing his throat awkwardly. “His hormone levels are all over the place. You saw him before, he’s a mess.”
Gen made an offended sound against Senku’s neck, nipping at his collar in retaliation before ducking back into his shoulder. Chrome snickered but went rigid when Gen’s eyes flicked to him again, sharp and warning.
He raised his hands, taking a few steps back, “Hey, relax. Look bro, I’m gonna head back to work but you might wanna… figure this out before you come back?”
“Figure what out?” Senku asked, just a bit too quickly, too sharply.
Chrome gestured at them, Gen purring contentedly now that there was more distance between him and the pair. Suddenly, the omega started to lead Senku away from the shipyard and despite glowering at Chrome when the other alpha snickered, Senku let himself be herded. Any time Senku tried to stop or say something, Gen would chirr disapprovingly and pull at his arm, and despite his best efforts he found himself practically bullied into the hut they shared on the outskirts of the camp. Gen had been busy in the time since Senku had left that morning, a large pile of blankets and other soft materials having appeared where their bedrolls would usually go. Senku could see a blanket he recognized from the observatory back at the village as well as a few scraps poking out that were definitely his winter coat and a few spare wrist wraps.
Brow knitting in confusion, Senku barely had a moment to acknowledge the sudden appearance of an actual nest when Gen nuzzled into his jaw, brushing against the sensitive space right behind his ear. His irritation warred with an uncomfortable awareness he couldn’t quite categorize - frowning when he realized that he’d begun to absently pet up and down Gen’s side.
“You can’t just attack people, you know,”
“I warned him first. He ignored it,” Gen rubbed his nose against the space behind Senku’s ear again, pushing him in the direction of the nest. “He smelled wrong.”
Fighting back a shiver, Senku tsked. “That’s not a valid reason.”
“Is to me,” Gen replied simply. “I wasn’t going to actually hurt him.”
“You nearly dislocated his shoulder.”
Humming dismissively, Gen dropped into the pile of blankets and jerked Senku down with him. Grunting, Senku resolutely stayed on his knees despite Gen’s huff of disapproval at his reticence.
“Chrome’s right, you’re being weird,” he muttered, eyeing him warily. The cuddling he was used to, but as far as he knew Gen had never built an actual nest before - definitely not in the observatory, anyway, or any other living space they shared. And he certainly hadn’t ever dragged Senku back to one at any point.
He remembered Chrome pointing out the change in Gen’s scent and gave a few more sniffs, trying to suss out what he’d detected earlier. It definitely wasn't burning hair or anything vile, but a sweeter, almost spicier note that had him swaying closer without realizing. He found himself lowering down into the nest with an absent thought to something from school and omega scents…
Once an omega chooses a prospective mate, their scent will change in an effort to fend off any other suitors, in some cases becoming downright putrid to anyone but their chosen alpha. They will become territorial and possessive, building a nest if they have not already, and defending it and their alpha by any means necessary until a mating bond is formed
Senku didn’t realize he’d closed his eyes until they snapped open, jerking back despite the disappointed noise Gen made in response.
“You’re nesting.”
Gen blinked up at him, pupils dilated and face slightly flushed, looking more annoyed by him moving away than anything else.
“You don’t- you’ve never… you didn’t even tell me you were going to?”
He would have been embarrassed by how lost he sounded if Gen hadn’t taken that moment to shrug out of his haori and stretch leisurely, drawing attention to the curve of his lower back. Senku felt his brain skip like a scratched CD, fingers twitching absently.
“I told you I liked your coat,” Gen practically purred, settling back down, “and how it smelled,”
Senku stared at him and Gen lazily stared back, unrepentant. Tail-less but still somehow looking exactly like a contented cat caught in a sunbeam.
“This is, is-“ he waved his hand, searching for the right words, “mate behavior. It’s practically claim-adjacent!”
Gen’s scent shifted slightly, warm and pleased. “About time you noticed.”
Senku’s mouth worked uselessly for a few moments. Annoyingly, objectively, Gen wasn’t wrong. In hindsight, he’d allowed the behavior to go on far longer than was reasonable, paying no heed to how Gen’s actions had ramped up each cycle. Treating it like a minor inconvenience. A weird quirk of biology.
“I didn’t think you were serious,” he finally replied, knowing it was a weak excuse even as he said it.
Gen gave him an unimpressed look and Senku felt his cheeks heat up, mind betraying him immediately as it supplied memories he’d carefully filed away as irrelevant. Gen only ever cuddling up to him. The way his body language turned sharp and unwelcome when other alphas got too close, more so when another omega came close to Senku. How he practically melted at Senku’s touch. How easily he’d backed off from Kota the moment Senku had spoken.
The way he’d bitten him. Twice now. Not hard, not enough to break skin, but just enough to send a message.
“You didn’t push me away,” Gen hummed. “Didn’t tell me not to scent you or leave when I got territorial…” he smirked. “You let me.”
Senku blew out a breath and looked towards the ceiling, jaw tight as his brain ran through the data. Patterns, escalation, cause and effect - Gen’s behavior ramping up in intensity, his own growing tolerance to it, his acceptance of it.
The way Gen’s scent always seemed to light up parts of his brain and how his bite had sent lightning down his spine.
The looks Kohaku and the others gave him suddenly made a lot more sense.
At his silence, Gen seemed to deflate a little, “I’m not trying to trap you or anything, if you tell me you’re not interested I’ll back off. I’ll go somewhere else to ride it out and leave you alone.”
Senku barely bit back the growl in his own throat at the notion of Gen leaving. His instincts flared at the idea of the omega leaving their den, their nest, leaving him, at the possibility of him seeking out someone else. The idea settling hot and heavy in his chest.
“And if I don’t?” he asked, trying to pretend he wasn't pleased at the way Gen’s breath hitched just slightly.
“If you’re not not interested… I’d like to stay here. With you.”
Silence stretched between them as Senku’s logical brain fought against his rising instincts at the clear implication. An omega inviting an alpha back to their nest during their heat meant only one thing, and it certainly wasn’t just to cuddle.
“This is a bad idea,” he said finally, sinking back down into the nest but keeping some distance between them. “You’re in heat, so we are not doing anything permanent. No marks, no claims, no bites-“ he stressed the final word when he caught Gen staring at his neck. “Not until we can talk when you’re not all… hormonal.”
Gen rumbled with a purr, rolling to his knees and prowling closer, “You like me all hormonal.”
Senku didn’t move away or flinch as Gen forced him to lay down and adjusted the fabric around him to his liking. After a few minor shifts, Gen seemed pleased with his work, nodding to himself before slumping into the space he’d created next to Senku with a contented purr.
Staring up at the ceiling, Senku contemplated just how easily he’d given in, wondering absently how long it would take for the others to figure out where he’d gone and why. Though as Gen began to knead gently at his chest and abdomen, scent warm and soothing, he found he didn’t particularly care, relaxing and practically melting into the nest as his eyes drifted shut.
—
Senku wasn’t sure exactly when he fell asleep, but snapped awake at the sound of Gen growling and the pressure of the omega leaning his weight onto his chest.
“Hey, hey, chill! I was just wondering what was taking so long,” Chrome called as he slammed the door shut, Gen glowering at the slab of wood between them.
Senku huffed in annoyance, pushing Gen’s hand off his chest so he could sit up. The omega pressed more firmly against his side, relaxing just slightly but still growling. “Probably gonna be a few days before he lets anyone else in here, Chrome,”
“Ah… should I…” Chrome trailed off awkwardly and Senku stroked a hand over Gen’s back, realizing with a start that it was bare. “Do you need me to get some help?”
Senku opened his mouth to answer, stuttering over his words as Gen began pawing at him. Nuzzling into his neck and rubbing against him to scent him - behavior he was already accustomed to and expected.
What he wasn't accustomed to was Gen’s hands zeroing in on his lap, groping through his coat at his dick which was quickly growing far more interested in the current events.
“Shit!” Senku jolted, unintentionally rocking his hips into Gen’s hand - something that Gen seemed more than fine with based on the way his pheromones thickened around them. “Uh, don’t worry about it, Chrome, just…” he flinched when Gen’s hands wormed their way under his coat, long fingers stroking over his thighs and into his underwear. “I’ll be fi-hine!”
Gen gave a pleased chirr at the reaction, stroking him more deliberately as his other hand started yanking at his coat in an effort to get it off.
“What… oh! Oh…” Senku winced at Chrome’s tone, the embarrassed realization of what was going on behind the door clear in his voice. “I’ll, um… leave you to it? Have… fun?”
Chrome’s awkward wince was palpable and Senku listened as best he could to hear the footsteps fade away before pivoting his weight and pushing Gen down into the blankets.
“You little-“
He nearly swallowed his tongue when he finally managed to focus on Gen's face. The omega was flushed pink, pupils so dilated as to make his eyes appear black, lips wet and parting on panting little moans with every breath. He’d undressed at some point when Senku was asleep, a thin sheen of sweat covering miles of pale skin and the tantalizing smell of slick thick in the air.
“Senku-chan,” he crooned, arching his back and baring his neck as he tugged ineffectively at Senku’s coat in an effort to get him closer.
Senku was many things but at the end of the day he was human. At least that’s what he planned to tell himself when everything was said and done, shoving his face into Gen’s neck as he tore at his own clothes. He breathed deep, Gen’s scent heavy with heat pheromones and arousal, sweet and warm and inviting.
Fumbling with the clasps holding his coat closed, Senku found himself cradled between Gen’s thighs, poised over him and sucking on his throat. It was not a position he’d ever expected to be in, jittery with nerves and want and a weird boost of alpha confidence coming out of nowhere, but he rolled with it. Gen didn’t give him a chance to do anything else, hands stroking over his chest and sides as they were bared, moaning softly in his ear and writhing against him.
Cursing when the head of Gen’s dick stroked wetly over his abs, Senku finally dared to look down and barely bit back a moan at the sight. Gen's thighs spread wide, shiny with slick and erection heavy and leaking between them, Senku’s tenting the fabric still hung around his waist lewdly, jerking forward with barely restrained thrusts of his hips.
He knew the science behind it all - omega pheromones hitting his vomeronasal organ and triggering his limbic system into instinctual overdrive. Increased testosterone production and an influx of other hormones priming his dopamine receptors and the reward response in his brain for mating to be at the forefront of his mind.
Knowing the science did little to prepare him for how it felt.
And it felt overwhelming in the best possible way. Hips stuttering, Senku bit the inside of his cheek to stop himself from biting down on Gen’s collar bone, hands curling around his knees to force the omega’s legs up and out to better settle between them. Gen went easily, arms looping around his neck and pelvis rocking up to meet Senku’s in a lewd wave.
“This is a terrible idea,” Senku panted through grit teeth, wrestling his coat the rest of the way off and lining himself up. Gen grunted wordlessly, shifting and wriggling to try and force him in, head thrown back when they hit the mark and Senku slid inside with barely any resistance.
Hot. Wet. Tight. The three words echoed in a loop through Senku’s head as he trembled, barely managing to keep himself from going off immediately. His efforts were undermined by how Gen shuddered around him, obviously having no such concern, moaning and clenching through a shivering orgasm, cock pulsing wetly between their bellies.
The scent of his release had Senku’s hips moving before he could stop them, setting up an immediately punishing pace. The sound of skin slapping wetly together in concert with panting breaths and each high pitched moan punched out of the omega beneath him lit up parts of Senku’s brain he’d never considered before.
Claim. Breed. Mine.
Gen clawed at him, fingernails tracing hot, stinging lines over his shoulders and down his arms in between attempts to pull him closer. Senku was surprisingly able to stand his own against the urging, focused solely on getting the omega beneath him to come again so he could force himself deeper, do what his biology urged him to.
Ducking down, he mouthed at Gen’s chest, finding one of his nipples and sucking as he gave a particularly rough thrust. Gen went taut as a bowstring, what sounded like a pained sob wrenching its way out of his throat as his entire body seemed to pulse, clenching around him in rhythmic waves.
“Fuck, fuck…” Senku cursed, spine bowing as his orgasm hit, knot swollen but not nearly to the size he knew it would be in a few short hours after repeated catches. He felt Gen ripple and clench around him, drawing pulse after throbbing pulse of release, the omega gasping and shuddering through another orgasm as he was filled.
It felt like it went on forever, though once his brain finally started to get back online Senku realized it had been only a few minutes.
He knew he should be upset with himself for capitulating to his instincts. Should be disgusted by the sweat and the slick and the semen clinging to them, irked by the inability to pull away due to how tightly they were latched.
But as Gen pulled him down into a breathless kiss, all he felt was content. His omega was safely knotted underneath him, scent warm and satisfied, and Senku could practically feel the dopamine soaking into his brain like a sponge. He pulled back just far enough to rub his face against Gen’s neck, chuffing when he bared his throat obediently.
“Always manage to get your way, don’t you? Spoiled bastard…” he huffed, nuzzling in closer as his knot gave another pulse. Gen gave a contented mewl in response, eyes half-lidded and pleasure fogged as he rocked into it, legs having wrapped around Senku’s hips at some point and hands petting up the alpha’s chest and shoulders.
By the time Senku’s knot deflated, Gen was mostly asleep, practically dead weight as the alpha maneuvered them into a more comfortable position.
He knew at some point he’d need to venture out to get food and water if Gen hadn’t stocked up already, but he found himself surprisingly not dreading a walk-of-shame as much as he thought he would. He blamed it on alpha hormones and the flood of testosterone running through him, gathering Gen close and settling down into the blankets for a rest.
He'd need to be ready to go when Gen was, his omega was pretty clingy after all.