Title: Eighteen
Fandom: ST:XI
Rating: R/NC-17
Pairing: Chekov/Sulu(/Kirk)
Warnings: frank discussions of sex; AU; sillyness in general
Notes: First posted on LJ/DW/AO3. Written for the following prompt:

Chekov has part alien in him and he doesn't know. When he hits 18, it is mating season and without knowing it, he sends out a scent that attracts males to him. Guys are trying to hit on him and kiss him and Chekov doesn't understand why. The scent doesn't go away until he mates.

Bonus points if someone sits him down and tries to explain that he smells good.

Chekov/Scotty or Chekov/Sulu or Chekov/McCoy please.

Summary: Chekov discovers that he isn't as human as he thought he was. Shenanigans ensue.

Everything had started off normally.

His eighteenth birthday had come and gone without much fuss. He'd spent three days on some unsavory planets getting built up urges out of his system, got a lecture from Dr. McCoy about safe sex, and gotten into a massive fight alongside Scotty and a few of his crewmates in a bar.

Half a year later, something odd happened.

He woke with a raging hard-on. It wasn't anything new. He masturbated and moved on. But it kept coming back, and he was horny all the time, and the staring just made it worse. Female Ensigns slapped his ass. A few male ones left him flowers. Scotty grabbed him in the mess hall and slammed their lips together in a surprise of an Oklahoma Hello. Everyone who didn't hit on him stared, as if he was food and they were dying (wo)men.

The Captain's appreciative eyes admiring him weren't new; that had been going on pretty overtly since Pavel had turned eighteen. Sulu's devouring looks, however, were unexpected and distracting enough that Chekov had to excuse himself and dash to sickbay.

The doctor frowned at him as he babbled out an explanation, panting and jumping every time a leering crewmember walked past.

"I was accosted in a turbolift!" Pavel shouts at the end of it, arms waving.

Dr. McCoy nods, clearly thinking, as he pulls out a few pieces of rather intimidating medical equipment. "I'll run a few scans and do some tests if it'll make you feel better. You can hide in my office while you wait."

If Pavel hadn't known about the doctor's aversion to unexpected contact he would have kissed him, and he says as much. McCoy snorts and tells him to "skedaddle".

The doctor's office is as intimidating as the doctor himself, but Pavel can tell the chairs are designed to be as comfortable as possible.

Pavel sits in one away from the door, trying to stay out of the line of sight in case.

Whatever parade of crewmen as comes to search him out is turned back by Dr. McCoy's threatening glower and hair trigger temper. It feels like it's been forever by the time the doctor comes to fetch him, but Chekov is grateful for the break anyway.

The doctor looks like he's torn between exasperated and greatly amused. Pavel takes from this that whatever it is isn't good, but it's not life threatening.

McCoy locks the door to his office first, then eases himself into his chair and gets comfortable. Pavel takes from this that the problem is serious, but not particularly urgent.

McCoy sighs. "I've got good news and bad news. Which do you want?"

"I…I don't…"

"Do you have any non humans in your family?"

Pavel blinks at the sudden turn in conversation. "I…not that I know of."

McCoy sucks his teeth. "Well, then. Good news: I'm pretty sure I know what's going on. Bad news: I'm pretty sure I know what's going on."

Pavel stares.

McCoy pauses again. "You're sure you don't have anything other than human in you?"

"I told you, I don't know. I'll have to ask."

"You do that. Until then…" McCoy sighed. "You're putting out heaps of pheromones. More than any human can claim at once, slightly different in make-up than anything a human can produce. Apparently – whatever species you are, if you're part alien and it's not something else – this is mating season or something like it. I can't tell you how long it'll last, because I don't know what you are."

"You are sure?"

The doctor raises an eyebrow.

Chekov blushes. "I'm sorry, it's just…is it dangerous? Will it kill me like Mr. Spock's?"

McCoy shakes his head. "Not so far as I can tell. It's annoying, inconvenient, and it'll cause a heck of a lot of trouble, but it sure as hell ain't dangerous. If you've got someone you like to fuck on the regular, get on it now."

"And…if I don't have anyone?"

McCoy shrugs. "Find one, or don't. I'll tell you if this becomes a 'fuck-or-die' situation."

Pavel nods and stands. He pauses facing the door, rethinking.

The doctor rolls his eyes. "You can hide in here until dinner. After that you're on your own."

Chekov figures he has a few things working against him in this instance. The first is that he's horny – incredibly, mind bogglingly, irrationally, painfully horny. He's thinking about sex constantly, he's always hard, he has to literally restrain himself from jumping the next person to so much as glance in his direction. The second is just that – everyone keeps looking at him. The doctor has somehow managed to scare everyone out of molesting him, but that doesn't stop the flirting and the random inappropriate touches. Half the time he finds himself flirting back, and it's so hard to reign himself in. Thirdly, this has never happened before, and the only frame of reference he has for understanding it is Mr. Spock's Vulcan thing, which is very clearly nothing like what Pavel is experiencing.

He's thought about just picking someone, but he doesn't know if just once will do it, or if there's something new and binding that will result. He doesn't want to drag any one into some mess like that – not someone he doesn't know very well.

Hikaru blatantly stares at him during quiet moments on the bridge, making lewd comments. He seems so sure that he'd blow Pavel's mind in bed, almost smug about it even though nothing's happened. Pavel wants to wipe that smug off his face with his teeth and his cock.

And the captain. Pavel is sure that man edges Sulu on. When they are off duty he adds to it, whispering propositions as they pass in the hall, pressing against Pavel in a turbolift. Kirk should know better than to tease; Pavel would teach him…

This entire thing is driving him insane.

"You could always just pick someone," the doctor says when Pavel complains. "Jim will end up knowing anyway, and he won't care so long as he gets off without losing his dick."

Pavel scrunches up his eyes. "He is in a relationship with Sulu."

"And?" Dr. McCoy raises his eyebrows. "The only thing that changes is that they have sex with each other on the regular and sometimes share quarters. If you're okay with the other knowing about it you can sleep with either of them. Or both of them."

Pavel contemplates this. "Both of them? At the same time?"

"Maybe. Or different times. Or never. That's not something I want to talk about with you."

Two days later – almost two weeks since this whole mess started – Hikaru waltzes into sickbay with a few bruises. While he waits for the doctor to get to him he invades Pavel's personal space, hands on either side of Pavel's hips where the young ensign is sitting on a biobed. He leans in close and opens his mouth, but Pavel speaks first.

"Wanna fuck?"

Hikaru blinks, thrown by the change in routine. Pavel grabs him by the hair impatiently and smashes their lips together, his free hand pulling roughly at Hikaru's shirt.

Somewhere nearby, Dr. McCoy makes a disgusted noise and turns to go the other way, calling over his shoulder. "Not in my sickbay!"

Hikaru pulls away with a gasp. "Whoa," he breathes. "You…"

"Shut up!" Pavel growls, cutting him off. "This is what we're going to do: we will go to my quarters and I will fuck you until you can no longer move, and you will listen to me and do as I tell you."

The part of him that's thinking clearly isn't quite sure where this is coming from, but the rest of him is too relieved by the prospect of a satisfying end to this madness to care.

He releases Hikaru's hair and seizes his arm in a cruel grip. "Come."

Hikaru does.