Chapter Text
Taehyung didn't know how he could be so stupid as to put himself into this position. He should have seen it coming, recognized the warning signs, but hindsight- as they say- is 20/20. It had all started so subtly, each individual occurrence seemingly removed from one another, but when looked back upon, made for a rather clear trend. The warning signs had been there, it was just no one knew they had to look for them.
The first sign had probably been pre-debut, but even that one was questionable.
All of their group, but one, had presented by the time the announcement came that they had been selected to take part in a seven-member group. Kim Seokjin, Min Yoongi, Jung Hoseok, and Kim Namjoon- the eldest four- were all Betas. Himself and Park Jimin, his friend from school even before they had become trainees, had presented as Omegas the year before. Jeon Jungkook, the youngest by almost two years, had yet to present, but judging by his demeanor was thought to likely be a Beta as well.
Jungkook was polite, even-tempered, and perhaps just the slightest bit clingy to Taehyung and Jimin, but kids, no matter their secondary gender, tended to be like that around Omegas. They brushed it off. Jungkook was still young, still a child by their standards, and they were all entering a strange new world with only each other as support.
Secretly, Taehyung liked being looked up to by the youngest member. He liked being called 'hyung', missed being there for his own brother and sister, and so he basked in being given the chance to be one away from his home as well. While Jimin tolerated Jungkook's behavior- he had a younger sibling as well- Taehyung reveled in it.
By the time they finally debuted, Jungkook still had yet to present any outstanding characteristics for any of the three genders, but he was still well within the normal time frame. His need for touch and acknowledgement hadn't decreased, especially from the Omegas, though he seemed to start to prefer Jimin over Taehyung for that. Taehyung may have been slightly jealous, since Jimin disliked others invading his personal space, and Taehyung would have gladly swept Jungkook up into his open arms. He shrugged the feeling off, however. Jungkook gave off the presence of a particularly friendly, though still picky, housecat. He probably went to Jimin because the other boy didn't bother him, unlike Taehyung, who draped himself over their youngest member as much as possible, just to be annoying, as all good older brothers must be.
That should have been the first clue, he'll think later.
The second was how easily Jungkook gained muscle. Again, this was difficult to substantiate as Jimin also had no difficulty in adding on lean mass, despite being an Omega. Taehyung, on the other hand, struggled for every scrap of definition he could get and was generally lazy enough not to find the extra exertion worth it.
Jungkook also suddenly shot up several centimeters from the time he turned seventeen until he hit nineteen, coming even with Taehyung, who was himself rather tall for one of his secondary gender.
Really, their whole group seemed to subvert all of the stereotypes afforded to Betas and Omegas. Yoongi was too anti-social, Seokjin was too hot-tempered, Hoseok too loud, and Namjoon too assertive to be Betas. Add in Taehyung's height and the muscle normally hidden under Jimin's clothes for the Omega side, and none of them fit into the boxes others had designated for them.
So, that was clue number two swept under the rug and promptly ignored.
Other clues, like Jungkook's perceived moodiness, were chalked up to him being a teenager, and being so young when they all started training seriously. They spent long, difficult days together. It was bound to breed some resentment, some ire even, from among them, and since Jungkook was going through the same difficult time that all teenagers went through, more leeway was given to him for those times.
Perhaps it should not have been.
By the time Jungkook's 20th birthday rolled around, he had not shown any signs of having gone into heat, nor any characteristics of an Alpha. He was officially given the stamp of 'Beta' at his last physical, what they all thought he would be anyway, despite not having the hormone drop most Betas went through at puberty, and with the addition of some quirks. They all had quirks that made them unfit for the narrow view others had; it was why they got along so well.
Things went on as they always did after that. They practiced, and performed, and put everything they had into being the best idol group out there.
Their efforts paid off tremendously. The long hours they put in had come to fruition. They dominated Billboard charts, they went to America , and then they came home to do it all over again.
Taehyung bought an apartment. It was the one luxury he allowed himself to have, a space to call his own, filled with all the things he wanted. It was the one instance where he gave into his nature, creating a nest for himself that he felt safe and comfortable in, to return to after long days and even longer nights.
However, there were nights when practice went long and he was exhausted from the day. On those nights, he went back to the dorm some of the members still shared and collapsed on the nearest available surface.
On one such night, Taehyung allowed himself into the dorm room, stumbled into the shower, stole a set of clothes from Jungkook's room, and then collapsed on the couch. He had turned on some forgettable action movie, and within minutes, he was asleep.
He woke up to something hot and heavy over him, and a wet, wriggling sensation on his neck. The thing at his neck tickled and he lazily swatted at it. And then, from above, he heard:
"Taehyunggie-hyung, you smell so good."
His eyes popped open. Above him was Jungkook, in all his pierced, tattooed glory. The younger man's eyes were narrowed, nostrils flaring, and the horror of realization crashed down on him.
Due to the stress of their schedules, both Jimin and Taehyung's heats were irregular. They were also usually rather light, easy to deal with, and they never worried about them interfering with their scheduled events. Taehyung also had it on good authority- a.k.a other Alphas not related to him- that for an Omega, Taehyung did not smell particularly good. His scent was an herbal and spice mixture, not particularly bad, but quite unlike the usual sweet scents of other Omegas. Even Jimin had a hint of vanilla to mellow his musky sandalwood.
Taehyung smelled like someone preparing to roast a duck. It wasn't offensive, and the combination of spices was generally pleasing, but it wasn't what most Alphas looked for in an Omega.
The slick sensation returned, and Taehyung realized that Jungkook was licking his neck, right over a scent gland. He tried to push him off, but though they were nearly the same height, Jungkook had packed on much more muscle mass over the years and outweighed Taehyung by a good 15 to 20 pounds.
He took a deep breath in and that was his second mistake. Jungkook smelled undeniably like an Alpha, all cinnamon and coriander and pepper, and cedar- and, huh, a lot of those were scents people told Taehyung he had. Strange.
Still, to Taehyung, Jungkook smelled good. Masculine. Ready. Virile. And then Taehyung could feel a creeping wetness from between his thighs and he groaned. Why, oh why, did he have to go into heat the night Jungkook decided to present, almost four years late?
This wasn't his first heat, however. He wasn't ruled by his hormones and neither was Jungkook, for all it might have felt like it, though he had heard first ruts for Alphas were the hardest. The sudden influx of hormones caused a surge of adrenaline that seemed to override all other senses.
It was the same for Omegas. That first heat had been the only time Taehyung had begged off of practice, his mind mired with too many emotions, his body fluctuating between being too hot and then too cold. He had stayed in bed that day and by the next afternoon had felt much better. Every heat after that had been a shadow of the first, easily manageable.
This one now reminded him of that long ago first, making his mind feel clouded and hazy. He didn't know if it was because he was in the presence of an Alpha- but, no, he'd spent one or two heats with other Alphas before and had never felt like this with any of them. Perhaps it was because Jungkook was unconsciously throwing out strong pheromones, unable to rein himself in due to his lack of experience.
He tried to push again. "Jungkook-ah, you need to control yourself."
For a long moment, he didn't think Jungkook heard him. Then, from somewhere around his neck, he heard, "I know, hyung. But I don't know how."
There was frustration in Jungkook's voice, a sort of sick despair at his body's betrayal as it refused to listen to him. Taehyung's collar was damp, and he realized that Jungkook was crying, tears silently tracking down his face to catch in the material of Jungkook's own shirt, and how stupid was it for Taehyung to wear Jungkook's clothes on today of all days?
But, he always wore Jungkook's clothes. Jungkook was the most similar in size to him, and with his broader frame, his shirts hung off of Taehyung, just the way he liked. It had never occurred to him that he was putting Jungkook's scent all over him; he had never thought it would be a problem. Jungkook was a Beta after all.
Except, apparently, Jungkook wasn't a Beta. He was an Alpha. An extremely late-blooming Alpha.
If this really was Jungkook's first rut, then Taehyung was the one in charge here. He was older, had been dealing with the complex emotions that the hormonal changes wrought for longer, and was able to keep his mind even as desire coursed through him. If things kept going this way, if there were consequences from this night, it would be Taehyung that would be held accountable.
Taehyung did his best to calm himself. Jungkook had already wormed a hand under his shirt, his skin hot and insistent against Taehyung's own as it climbed up his torso. "Jungkook," he called sternly. "You need to stop." He put as much force as he could in his voice.
"I want to, hyung." Jungkook repeated, even as his fingers found a nipple. "But, it's like my body won't listen. All I can smell is you, all I can hear is you. It's like you've invaded my senses, and I need to dive into you even deeper, all the while my mind is shouting at me that this is wrong."
Well, fuck.
He'd heard of this phenomenon, a holdover from ancient times where Alphas fought over the best Omegas and Betas for breeding rights. The practice had fallen out over time, of course, their senses had become dulled as reason took precedence over following instinct. Still, there were times when those old proclivities took hold, most notably on an Alpha's first rut or an Omega's first heat, but sometime genetics just liked to select an unlucky few to fuck with.
Usually, it wasn't an issue. In the present day, Alpha and Omega cycles rarely lined up, unless they spent a significant amount of time together. The person would recognize the symptoms of an oncoming cycle and take the appropriate steps to minimize their effect on others. Issues really only arose when a new Alpha and new Omega happened to line up and there was no outside influence to exert reason.
Or a newly awakened Alpha caught an unaware Omega alone and was able to pin said Omega before he even knew what was happening.
"Jungkook, think," he tried again. "Do you even want this with me?"
His heart jumped into his throat, somewhat afraid of what Jungkook would say. He knew the answer, had seen the looks and favoritism Jungkook had shown towards Jimin, and had tried not to think about how he wished Jungkook would look at him that way instead. He only wanted Jungkook’s brotherly affection, he told himself.
Jimin was mostly indifferent to- though very aware of- Jungkook's fumbling flirtations, doing his best to redirect them without outright rejecting the younger man. Until Jungkook confessed, Jimin didn't want to assume, he had told Taehyung one night when they had both been drinking, but he also didn't want to encourage any sort of crush. Jimin was determined to remain friends with Jungkook, but also just as determined not to be tied down to any one person. He wasn't ready for that, he had said. He wasn't sure he would ever be ready for that.
"No," he choked out, looking devastated even as he said it. "But I don't think I can stop."
It had hurt more than he thought it would, hearing it spoken out loud, but yet still feeling Jungkook hard and insistent against his thigh. He closed his eyes against the pain, pushing it down to try and think logically. By this point, his shirt had been rucked up under his armpits as those hot hands continued to explore the skin of his torso.
"Okay, Jungkook, I need you to listen to me. Can you do that?" He hooked a finger under the other man's chin, forcing his head up and away from where he had been busy sucking a bruise into the center of Taehyung's chest.
"I'll try," Jungkook panted.
Taehyung sighed. "We have a few options, I think. I'll lay them out and you tell me which you want to do." He caught Jungkook's gaze. "No judgement, okay? Whatever you choose, I swear I'll abide by it."
"What about you, hyung?"
He shook his head. "Don't worry about me. I'll be fine. I have more experience with this than you do, remember?"
Unexpectedly, that elicited a growl from Jungkook, opposite of the calming effect he had hoped it would have.
"Hyung, I think… I think it's a bad idea to talk about any other experiences you might have had." The expression on Jungkook's face would have been comical if the situation wasn't so serious, anger warring with sullenness at Taehyung's words.
"Right. Sorry." Damn, Jungkook was further gone than Taehyung had hoped. "I just meant because I'm older than you and heats have a similar effect on an Omega's brain chemistry that an Alpha's rut does."
Immediately, Jungkook's expression cleared. "Oh, okay." He darted down and licked a stripe up Taehyung's chin, then immediately pulled back, looking chagrined and vaguely disgusted with himself. "Sorry."
Taehyung nearly sighed again. "It's fine. Well, it's not, but- look, let's just take it as read that neither of us are exactly where we want to be right now and save the apologies for later, okay?" It wasn't even a lie. While Taehyung might have dreamed of similar scenarios before, he'd always imagined Jungkook reciprocating his affections. Sex without love, at least in regards to Jungkook, was the farthest thing from what he wanted.
Jungkook nodded solemnly.
"Okay, so, options."
"I don't think I can stop touching you," Jungkook immediately interjected.
"I'm not asking you to."
Jungkook sighed in obvious relief. "Good." Then he pulled a sour face, even as he leaned in to take a large sniff at Taehyung's neck. "This fucking sucks," he mumbled into the space between shoulder and neck.
"I know," Taehyung replied, petting Jungkook's hair even as his heart squeezed in pain at the words. "Sorry."
"You told me we should stop apologizing, hyung."
Taehyung gave a light smack to the back of Jungkook's head. "Shut up. I'm older than you, just do as I say."
"Okay." By this point, Jungkook had worked his way back down to one of Taehyung's nipples, giving it a tentative lick, then a more firm one that elicited an unintended moan from Taehyung.
"Hey, Jungkook?" Lust was starting to cloud his thoughts. For someone who Taehyung assumed was relatively inexperienced, Jungkook was extremely good at finding which spots made Taehyung twitch.
"Yeah," Jungkook mumbled around sensitive flesh.
"Do you feel any calmer now? You've been pretty responsive and reasonable the whole time we've been talking." Taehyung was holding out some hope that the conversation between them had distracted Jungkook enough from his immediate need that reason might reassert itself. "Maybe you could-"
Before Taehyung could even finish his sentence, Jungkook growled, nipping down on a sensitive bud and shoving his hands into the back of his jeans. "I'll take that as a 'no'."
"I think it's getting worse, actually" Jungkook panted into his skin. "I think the talking is just delaying it."
"Right. Okay. Options." Taehyung thought quickly. "Option one: I fight you off." He didn't actually hold out much hope for winning, Jungkook was heavier than him and practiced boxing in his spare time, but he could try.
"Hyung, I don't think you're gonna win that one. You can't even move me as it is." Jungkook had taken to squeezing his ass cheeks now, though still over his underwear, thankfully.
Taehyung leveled him with a look. "I mean to really fight, Jungkook." He said the name without his usual addition to it, letting the younger man know he was dead serious. "The kind where I bite and scratch, where we both end up bloody and bruised."
He could see Jungkook digest that for a moment before shaking his head, withdrawing his hands from Taehyung's pants to spread them over his abdomen again. "I don't want to hurt you."
And Taehyung didn't want to be hurt. Or hurt Jungkook. But, he would, if Jungkook decided that was the best option.
Truthfully, there was also a part of Taehyung that feared he wouldn't fight as hard as he could. That he would let Jungkook win, let the younger man push him down and bite into him.
He really didn't want to test that part of himself.
"Second option: we simulate what your body really wants, but don't go all the way."
Jungkook licked over his scent gland again, catching a hint of tooth on the way. Panicking, Taehyung pushed at him with one hand while clapping the other over the spot. Jungkook gave a disgruntled growl, but left it be. For now. Taehyung had no idea if it would stay that way; if this is the worst Jungkook would get, or if there was still more to come.
"How?"
"Intercrural sex." He tried not to blush at the words, but could tell his ears were turning red by how warm they felt.
"What's that?" Jungkook had moved on to his chest again, sucking and nipping lightly at various spots. He had also added a slight rocking motion against Taehyung's thigh, rubbing his not-so-inconsiderable length against him.
Taehyung forgot the question. "It's um- it's-" He panted with the effort to remain focused. Sane. "You fuck my thighs," he finally managed to get out.
"Oh."
He couldn't tell from the tone if Jungkook was disappointed in the option or intrigued, though Taehyung would have bet on the former. He had a feeling Jungkook was hoping to get out of this without them fucking or fighting. Unfortunately, since Jungkook's body seemed to be almost completely separated from his senses, Taehyung didn't think that was likely.
"The third option?"
Taehyung winced, partially from the question and its answer, and partially because Jungkook's fingers had found the waistband at the front of his pants and was playing with the trail of hair he had found under it.
"A more extreme version of option two; we have sex."
Jungkook actually pulled back a bit at that and Taehyung had a brief thought of trying to throw Jungkook off of him until he saw the way his pupils dilated. "Doesn't that carry the risk of us mating?"
"I'd cover my neck."
The younger man was quiet for a long moment. "Any other options?" The button of his jeans came undone.
"We draw this out as long as possible and hope someone else comes home in time to pull you off?" He was being mostly sarcastic. As far he knew, no one else was coming back to the dorm tonight. The last buses and trains had stopped running hours ago.
Jungkook knew that as well. "Let's go with option two," he finally said. "With the caveat that if I try to go further than that, you fight me off." He looked so resigned, so miserable at the thought, that Taehyung just had to ask.
"Are you sure?"
"No, but I don't want to hurt you and my body is clearly deciding things on its own," he gestured to Taehyung's disheveled state. "It carries the least risk of harm for both of us, too, right?"
"I'm sorry," Taehyung apologized.
Jungkook shakes his head. "Don't be." He starts trying to work Taehyung's pants off, but he catches Jungkook by the wrist before he gets more than an inch or two.
"Do you think we can go to your room? It would be more comfortable there." When he sees Jungkook's indecisive look, he adds, "and more private."
Almost immediately, Jungkook bounces off of him and scoops him up into his arms in a bridal carry. Startled, Taehyung loops his arms around Jungkook's neck. He'd known the other man was strong, but to pick him up almost like he weighed nothing… It made something primal shiver deep in Taehyung's bones.
Once they made it into the Jungkook's room, Taehyung was unceremoniously flung onto the bed, the door kicked shut and locked behind them. Seconds later, Jungkook followed him onto the mattress, pulling at Taehyung's clothes.
Embarrassingly, Taehyung felt another warm gush from between his thighs as Jungkook pulled his pants off. "What's that," the younger man asked as he stared fixedly at what Taehyung could only presume was the new wet spot on the back of his underwear.
"You had anatomy class, right?"
"Yeah." Already, Jungkook seemed distracted from his question, exploring Taehyung's thighs and nosing cautiously at the damp material.
"When an Omega is aroused or in heat, they produce their own lubricant to make sex easier." He tried to stay clinical with his descriptions, but it was difficult when all he wanted was to shout at Jungkook to stop teasing him and shove his cock in already. And the younger man had barely touched him. It was embarrassing how turned on Taehyung felt at being under the younger man.
Jungkook left his explorations to pull off Taehyung's underwear and then his own clothes. Finally, they were both naked except for the shirt still tucked far up under Taehyung's arms. "Oh. Right. Forgot."
It wasn't a good sign that Jungkook's sentences were getting shorter. The hindbrain was slowly taking over. Quickly, Taehyung got himself into position, pressing his legs closed and drawing his knees up. "Come here." He beckoned Jungkook closer.
Cautiously, obviously confused as to what Taehyung wanted him to do, Jungkook shuffled forward on his knees. Doing his best not to think too much about it, Taehyung slung his legs up over one shoulder, reached for Jungkook's dick, and pulled him closer, lining him up with Taehyung's closed legs. "Here."
Luckily, Jungkook got the hint right away, thrusting between them without hesitation. His face completely changed as he slid in between Taehyung's thighs. “Oh.” And that was a completely different noise from earlier. This one was surprised, pleased, and Taehyung could see Jungkook’s eyelids flutter at the sensation of his dick being enclosed in a warm, damp space.
The first time, Jungkook doesn’t last long. Only a dozen or so thrusts later, he was coming all over Taehyung’s thighs, his groin, and nearly up to his chest. Taehyung was achingly hard, but he pushed it down to ask, ”again?”
Jungkook nodded, and Taehyung could tell he was in the full grip of his rut now. His eyes were wide, unseeing. Jungkook thrust doggedly at him until he came again. The third time, Jungkook leaned down, bending Taehyung in half, to nip at his neck. Reflexively, he pushed Jungkook’s head to the side, slapping his hand over the vulnerable area. Pulling his hand away, there was a slight stain of blood, but he hadn’t gotten the scent gland directly, it felt like. Plus, they weren’t actually fucking. Everything was fine.
Taehyung wasn’t sure for how long they continued that way. He knew at one point Jungkook had gotten him onto his front, his cock running hot over Taehyung’s hole before he was able to pull away far enough to redirect Jungkook’s attention back to his legs. This time, Jungkook’s dick brushed up against the back of Taehyung’s balls, teasing the sensitive flesh. He’d also grabbed hold of Taehyung’s ass, pulling his cheeks wide apart and running a thumb over the damp, swollen entrance, causing Taehyung to keen.
Before this, Taehyung hadn’t been aware he could make such a noise. The sound garnered an answering groan from Jungkook, a thumb pressed deeper inside, and then the tell-tale twitch of the man behind him coming once again. It was enough to send Taehyung over as well, shuddering violently as he came after what felt like hours of being on edge.
As he came down from his orgasm, Jungkook collapsed against Taehyung’s back, nearly flattening him with his bulk. “Jungkook?”
No response.
With very little finesse, he tipped over onto his side, dumping the other man off of him. For several long seconds, he just breathed, replaying what had happened between them.
Fuck. That had really happened. The proof was in the air, on the bed, and all over Taehyung himself.
Jungkook had presented as an Alpha, likely thrown into a rut by Taehyung’s unexpected heat. They’d done nearly everything but penetrative sex, something Taehyung would have been happy about under any other circumstance except this one. When he had imagined being with Jungkook, on the rare occasions that he had let himself imagine it, he’d thought it would include a lot more mutual consent and not semi-forced sex under duress for both parties.
He’d imagined Jungkook in love with him, not in love with someone else while mindlessly fucking Taehyung's thighs to get off.
Quietly, he sat up. He glanced over at Jungkook, but saw that the other man was well and truly out. As silently as he could, he got off the bed, borrowed Jungkook's shower to clean himself, wiped off Jungkook, and then tucked the younger man under the covers.
As soon as he was done, he left the dorm.
Once he was downstairs, outside the complex, he placed a call to their manager. The man answered on the third ring. “V?”
“Can you come get me? Or send someone to get me?” He tried to keep the strain out of his voice, but he must not have done a very good job of it, because the manager sounded much more alert than when he had first answered.
“Are you alright? Where are you?”
Taehyung dug the toe of his shoe into a crack in the sidewalk. “I’m fine, just- I’ll explain when you get here. I’m at the dorm.” He bit his lip, thinking. “And, you should probably send Jungkook to see a doctor as soon as possible.”
He could hear the other man moving around, probably getting dressed as he talked to Taehyung on speaker. “You can’t stay at the dorm? Did something happen with Jungkook? Is he okay?”
“No, well, just… I think he’s an Alpha.”
There’s a large pause, an absolute lack of sound from the other end of the line, then the manager spoke again. “V, that can’t be possible. He would have presented years ago.”
“I know, but- well, I’m not sure. All I know is that I went into heat and Jungkook was very interested, saying he felt weird and trying to pin me, and-” He cut himself off before he could say more. Jungkook wasn’t at fault here. Taehyung was. He should have tried harder to deescalate the situation instead of caving into his desire to be touched by the other man.
“Okay,” their manager soothed. “Are you sure you’re okay?”
He nodded, even though the other man couldn't see it. “Yeah. I managed to convince him to lock himself in his room so that I could leave, but you didn’t see him. I know what an Alpha in rut looks like, and he definitely looked like it.”
“Aright. I’ll be there in less than twenty to take you home. And we’ll set up an appointment with the physician for Jungkook tomorrow.”
“Okay. Thanks. Sorry to bother you.”
“Don’t be. It’s what I’m here for,” the manager said before hanging up.
Taehyung found a bench to curl up on a little ways away from in front of the building and settled in to wait. True to his word, their manager pulled up with several minutes to spare. “Come on,” he said, holding the door open for Taehyung. “Let’s get you home.”
Home sounded wonderful. Curling up in his own place, feeling safe and secure, was just what he needed. On the way to his apartment complex, Taehyung relayed a watered-down version of what had occurred between him and Jungkook. He downplayed the extent to which Jungkook seemingly could not control himself, and said he got out of there before anything more serious happened.
By the time he was dropped off at home he was beyond exhausted. He let himself into his apartment, kicked off his shoes, and fell into bed. He was asleep within seconds.