Work Header

The Scientific Method

Chapter Text

Stiles and Scott are in detention—again—when the thought occurs to him.


It’s not his fault. There was a whole thing with a chupacabra in the girls’ locker room, and what were they supposed to do, let it eat the girls’ underwear? Stiles is way too much of a gentleman for that. Also, he’s a little too used to random werewolves climbing in his bedroom window to worry much about propriety. Besides, chupacabras (chupacabrae? What the hell is the plural for “goat-sucker”?) are totally dangerous. This school is lucky he and Scott got the thing’s carcass out the window so Derek could dispose of it before the girls came back in from gym class.


Who the fuck let a chupacabra into the school anyway?


Anyway, so Stiles is in detention—again—helping Mr. Myers prepare worksheets for his ninth grade health class, when it happens.


He stares down at the diagram in consideration for about half a second, and then Mr. Myers goes to take a cell phone call in the hallway, and Stiles turns to Scott and unloads the question. “Hey, so werewolves are immune to STDs and stuff, right?”


Scott barely looks up from stapling. “Uh, I mean, I guess so? Derek and I don’t exactly have the kind of relationship where I ask him about sex.”


Stiles’s brain hangs on that for a few seconds, because the very idea of Scott and Derek and sex in the same sentence is just so much no. Then he plows right on ahead with, “So like, you just assume it works the same as for humans and hope for the best, right?” because dear God he cannot get more specific without risking overexposure to Scott’s sex life with Allison. Stiles has enough mental scars from the supernatural creature asskicking they do every week, thanks.


By now Scott has picked up that Stiles is dancing around a particular issue, so he stops what he’s doing and looks over. “Yeah…?”


Oh, how to broach this subject without risking trauma to the both of them. Stiles’s life was so much easier before his BFF got super powers. “But, so, werewolves have super strength, right? And super speed. And better vision, and better muscle control, and healing powers, and stuff. And some of that’s probably, like, genetic, if you can be born a werewolf. Right?”


“Yeah,” Scott says. From the perplexed look on his face, he doesn’t yet know where Stiles is going with this. “So?”


“So what if you have condom-defeating supersperm,” Stiles blurts, and Scott goes pale.


“Oh fuck.”




Scott is lucky Stiles is the undisputed research master of Beacon Hills High. And also that he has no shame, because going to the pharmacy to buy four different brands of condoms and six varieties of spermicide would be really awkward otherwise.


Okay, it’s still awkward, but because it’s Stiles, the bored checkout clerk barely even raises an eyebrow.


Fine, so she looks at him like he’s got a dick drawn on his face and is currently jerking it. Whatever.


Stiles digs his old science kit out of his closet, finds a fresh notebook to start devising his scientific method, and wonders where the fuck he is actually going to perform this miracle of cryptid research, because his dad thinks he is weird already, Stiles does not need to be asked pointed questions about why he has thirty-nine condoms and a liter of spermicidal lubricant and suspicious white stuff in petri dishes around his room.


Clearly this sort of thing is beneficial to the pack in general, so the only logical place for it is Derek’s kitchen. Plus, then Stiles can ask him about werewolf safe sex.


Sometimes Stiles’s life is fucked up in new and exciting ways.


Because Derek continues to make poor life choices, Stiles actually has a key to his apartment, so he shoots Scott a text and meets him at the front door. Their timing is really great today, so they’re most of the way to set up before Derek comes in and starts judging them.


“What,” Derek says, just like that, with no actual inflection at the end of what’s obviously a question. He looks back and forth between Stiles and Scott like he thinks maybe he misheard.


“Do condoms work for werewolf sperm, yes or no?” Stiles repeats, totally not at all enjoying the way the vein in Derek’s temple throbs. “This is really the sort of thing you should know, isn’t it? You’re the alpha, and no offense, you don’t totally suck at it anymore, but I still don’t think you’re ready to raise a litter of sourpuppies.”


Something flickers across Derek’s face then, too quickly for Stiles to catalogue it. “The issue has never come up,” he says a little stiffly, and Stiles—Stiles doesn’t even know what to do with that, because if he looked like Derek he would be getting laid, like, seventeen times a day. Also, there’s a terrible erectile dysfunction pun in there somewhere.


If Stiles were a less nosy and invasive person, he might wonder if Derek were actually a virgin, but nope, can’t be, because he had to let Stiles do that dangerous spell last week, and also Stiles has read the police reports and put together some extremely disturbing theories about Derek and Kate Argent that he will never speak of ever.


Anyway, what Stiles takes away from this is that Derek is not getting laid. Beauty is wasted on him. Disgraceful.


“Whatever. I’m going to need a sample.” Stiles picks up one of the sterile cups from the table—Scott stole them from the hospital when he dropped off his mom’s lunch—and shoves it at Derek’s chest.


Behind Stiles, Scott makes a noise suspiciously like a laugh. Keep it together, buddy, Stiles thinks. If Scott laughs at Derek over this, Derek’s going to need a new kitchen window, because he’s going to throw Scott through it.


Derek makes a face like a thundercloud. Abruptly Stiles realizes he still has his hand pressed to Derek’s chest, even though Derek is holding the cup now. He inhales sharply and pulls away.




“For science!” Stiles tells him quickly.


“Oh my God,” Scott says quietly. Yeah, Stiles can’t believe he got to say that either.


Derek’s hands do the Wolverine thing, and yep, okay, time for Stiles to defuse this situation ASAP. “Look, I’ve checked every resource I can come up with, and that’s saying something, because have you ever googled werewolf spooge? I should be getting hazard pay for that. I have trauma.” And inappropriate responses, but Stiles is never telling Derek that either. “Anyway, when you became Alpha, you got accelerated healing and a whole bunch of other mojo. Besides, you were born a werewolf. We need to compare your, uh, you know. To Scott’s. Unless you don’t ever plan to have sex again.”


Derek looks at the cup and clenches his jaw. The plastic creaks ominously.


“Dude, it’s not that complicated.” Or maybe it is? Maybe Derek’s, like, celibate or something? “Do you need instructions for jerkin’ the gherkin? Because that would explain so much.” No wonder he’s grouchy.


Derek snarls and stalks off into the apartment.


Scott says, “Dude.”


Stiles’s knees have turned to butter. “So we’re going to pretend I didn’t just offer Derek masturbation advice, right?”


Scott nods emphatically.




While Scott and Derek are busy collecting their respective samples (Stiles isn’t thinking about it), Stiles sets up his experiment. There are several petri dishes—yellow for Scott, red for Derek—a couple of large and vaguely phallic carrots to ensure uniform stretching of the condoms, the microscope, some slides, a bottle of stain, his stopwatch.


He makes it partway through the condom stretching before it occurs to him that he needs a control group.


“The things I do for this pack,” Stiles mutters as Scott comes back into the room, looking sheepish but determined, and slams the sample jar down on the counter. Still no sign of Derek. Maybe he has alpha werewolf stamina or something.


Scott shoots Stiles a vaguely alarmed look. Stiles really needs to get a better lid on his physical responses to these thoughts he can’t stop having. “Instructions are in the notebook,” he says briefly. Then he grabs his own sample jar and retires to the bathroom in shame.


He lasts about as long as it takes him to wonder if Derek can hear him in the next room over.




When he returns to the kitchen, there’s another sample cup beside Scott’s on the counter. Scott is kind of staring at it. Stiles doesn’t blame him. Way to make a guy feel inadequate, Derek.


“Right, so!” Stiles digs out the box of nitrile gloves Scott also stole from his mom’s work, grabs a pair, and smacks them into Scott’s chest. Because all their friends are basically werewolves and they cannot go around smelling like werewolf semen. That’s messed up. “First up: sperm motility!”


Scott says, “I really hate you,” but he smears a microscope slide and hands it over for Stiles to examine anyway.


After three quick checks in the microscope, Stiles scientifically ascertains that Scott’s sperm count is approximately the same as Stiles’s and that an eyedropper of Derek could knock up half of Beacon Hills.


“Dude, what?” Scott asks when he sees Stiles’s face.


Stiles steps back from the microscope and gestures for Scott to look, which he does, with his nose wrinkled hilariously.


“Dude!” Scott says again, only this time his voice is a compromise between what the fuck and reluctantly impressed.


“Right?” Stiles says, gesturing aimlessly.


Which is when Erica comes in, sniffing. “It smells like an orgy in here. What are you doing?”


Stiles explains.


At first, Erica looks nonplussed. Then Stiles gets to the part where: “—and I’m pretty sure Derek could knock up a dude if he tried hard enough,” and then she looks a little concerned.


Stiles tries really hard not to read into that.


“What about female werewolves?” Erica asks.


Stiles blinks, then looks at Scott, who shrugs. “What about them?”


She rolls her eyes. “Birth control, dumbass. You’re testing condoms for the guys, right?”


That’s one of the tests. There’s another one in another set of petri dishes, this time to determine how long the little swimmers can survive outside their host’s testicles.


But Erica has a point. If there’s a chance condoms are useless for contraception, there’s an equal chance crazy werewolf healing renders the pill irrelevant too. Stiles is going to need more sample cups. And probably a control group, or even two.


He wonders if Lydia is on the pill.




In a twist of events that surprises absolutely no one, Lydia is a way better research partner than Scott. Plus the smell of another werewolf doesn’t make her want to shred things. It is a mark of Stiles’s much-increased maturity, and probably also the fact that he’s given up on her as a lost cause, that he is completely fine with her handling his jizz in a completely nonsexy context.


Anyway, hooray for his new research partner—but unfortunately the swap also means Lydia is present when Derek comes back in (they’re on their second round of semen samples now; even Derek’s were mostly dead after two days) and observes Stiles’s condom-unrolling ritual. He’s getting really good at it. Even Lydia was impressed, once she got past the whole using-an-abnormally-large-carrot-as-a-fake-penis thing.


“What?” Stiles says defensively, carefully sliding a blunted pipette between the carrot and the condom to deposit little Dereks inside. He and Lydia have developed a mathematical formula that means he doesn’t actually have to put a full load (oh God his life, he’s not even trying to be dirty) of semen in a condom, which is good because probably even a werewolf dick would be chafing by now. “It’s important to be as accurate as possible, okay? That means the condom has to get unrolled on a vaguely phallic vegetable first!”


“As accurate as possible,” Derek repeats, expression unreadable.




Derek raises his eyebrows. “You’re going to need a bigger carrot.”


Oh my God.


Derek exits the kitchen stage left, and Stiles and Lydia exchange glances. This is probably the closest they’ve come to ever having anything in common. Jesus Christ, they are thinking about Derek’s penis together.


His life.


“Funny how Scott never mentioned that,” Lydia says neutrally once the moment is past.


Stiles has shared a locker room with Scott since they were old enough to need showers after gym class. It’s not like he looks, but he’s caught unavoidable glimpses now and again.


Fine, he looked.


The point is, Scott’s penis has not wolfed out. “Well, he wouldn’t,” Stiles mutters, and then they catch eyes again and make an unspoken agreement never to speak of this again.




The rest of the research takes about two months to complete, mainly due to the fact that Stiles and Lydia have to analyze two months’ worth of pee samples for hormone content. Scott sneaks them all into the hospital for some slightly more invasive tests Stiles blocks out of his memory, but it’s not like Erica can go the rest of her life without knowing this shit. It’s important.


With Allison as the human control and Lydia as the birth control control (a ridiculous redundancy), they discover female werewolves are basically baby machines waiting to happen. Surprise!


Erica is not impressed by this information, though she settles some when they discover the pill is effective, supermetabolism or no. And it’s a good thing too, because werewolf sperm and condoms, not as compatible as you might think.


Stiles is writing all this shit down in the notebook, or as he’s come to call it, the Stiles Stilinski Guide to Werewolf Fertility, but that’s all in general terms. These are his friends, and he and Lydia are their sort-of doctors in this scenario, so when the last of the experiment is cleaned up, and Lydia has clapped him on the shoulder (six months ago that would’ve given him a boner, pathetic), yanked off her gloves, and located her manicure kit (apparently nitrile is bad for her nails or something), they sit everyone down two-on-one.


Scott gets to go first.


“So the good news is Allison isn’t pregnant,” Stiles says, because after dealing with so many urine samples, seriously, he gets to do this his way. “The bad news is that’s sort of a fluke.”


Scott buries his face in his hands. “Remember the days when you never asked me about my sex life and I told you anyway? I regret those days, man. You are torturing me.”


Lydia snorts and buffs out an invisible imperfection on the nail on her ring finger.


“Shut up, I’m saving you from, like, an actual shotgun wedding. Or probably just the actual shotgun part.” Plus, this whole science experiment has just brought home the fact that Stiles is the only virgin left in Beacon Hills and all his friends are getting laid on a regular basis. Yet somehow he is the one doing the heavy lifting to make sure they don’t ruin their lives. So not fair. “The point is, the condom thing is only about seventy percent effective for you, and that’s over five minutes. I’m just going to assume you can last more than five minutes, so, congratulations on dodging a bullet. Like, almost literally.”


“Five—” Scott starts.


“Dude, preejaculate can totally contain sperm, I was in your health class, I know that you know this.”


Scott leans forward and thumps his head on the table.


The spermicide is more of the same, and it’s not even that effective for normal human contraception. Stiles advises Scott to take some kind of measure unless he wants to be a babydaddy, and Scott nods miserably and slinks out of the kitchen.


“Well, that went well,” Stiles tells Lydia afterward. One down, many to go. Boyd and Isaac are getting the Scott talk; something about the way the kanima interacted with the bite made Jackson sterile, so Lydia’s handling that on her own. “Do you want to advise Allison about the pill or shall I?”


“I’ll handle Allison and Jackson if you take Derek,” she says serenely, reaching for the nail polish.


Stiles doesn’t think there’s a good way out of this one.




Derek’s nose keeps twitching. It’s distracting.


“So, uh.” Stiles does not have the slightest clue how to begin this conversation, so he jumps right in. “You should maybe get in touch with any women you’ve had sex with since you became an alpha. Or, you know, before then. Because, like, your sperm count, dude, it’s—you could probably single-handedly repopulate the world after a zombie apocalypse.” He pauses, thinks about that. “Well, maybe not single, because you’d need at least one woman, and not with your hands. But you probably already have, like, kids. A lot of them.” Then he stops again, because he’s aware that was not the most sensitive way he could have broached the subject.


“I don’t,” Derek says. His nose is still twitching and he won’t meet Stiles’s eyes. “I… trust me. I’m sure.” Then he points out, “I did grow up this way, you know.”


So his parents did give him a werewolf safe-sex talk! Stiles pouts. “If you knew all this already, you could have saved us the effort. You said it had never come up!”


Derek looks up. His eyes are glassy. “I didn’t know everything. Not about how it would affect bitten wolves.” He hunches his shoulders. “And I didn’t know anything about what would happen with Erica. So. Thanks for helping with that.”


Great, now Stiles has made him feel like a bad alpha again. And just when he was starting to do better too. “It’s no problem. They’re—you’re,” he corrects, “my friends. Besides, I’m awesome at research.”


Derek doesn’t correct him, which Stiles takes as a compliment. But then Derek stands up abruptly and shoves his hands through his hair. “I have to go.”


It’s not the weirdest exit he’s ever made, so Stiles decides to let it be.




But a week later he has to dive headfirst back into the research.


Allison squirms. “I know this is weird, but I don’t have anyone else to….” She shrugs helplessly. “It’s not a problem for Lydia. She and Jackson aren’t together anymore. But ever since I started them, it’s like Scott doesn’t….”


Fuck Stiles’s life. His friend can’t go a week without sex and Stiles has to fix it. Seriously, this fucking sucks.


“She smells wrong,” Scott tells him miserably when he asks. Apparently the sexual frustration is getting to him, because he leaves clawmarks in the kitchen table. “I don’t know, okay? I can’t—”


Stiles repeats: fuck his life.


“That doesn’t even make any sense,” he says. “Like, I bugged you for samples, okay? Allison was not here. You are clearly capable of getting it up with or without her.”


Scott huffs. “Are you going to help us or not?”


Which is how Stiles ends up mixing Allison synthetic pheromones from recipes and ingredients he finds on the Internet.


“They’re supposed to mix with your natural scent,” Stiles tells her, passing over two bottles full. He’s got another couple for Erica and Lydia, just in case, because even though Stiles still thinks Jackson is a douche bag, dating a douche bag is still Lydia’s choice, and he respects that. “You just need a little. Like, microscopic amounts. Use the green cap most days. If you want to mimic a natural cycle, use the red cap before you, yeah, anyway. But I wouldn’t recommend it, like, the week of the full moon, if you can avoid it, because. Uh. Just trust me.”


Allison hugs him. “You’re the best.” She presses a quick peck to his cheek. “Seriously, Stiles. I owe you.” Then she picks up the tiny vial still resting on the table. “What’s this one?”


“Oh, that.” Stiles grins manically. “I call that one Werewolf Baby Bomb.”


Very carefully, she puts it down again and takes a step back. “Why?”


He’d really been hoping she wouldn’t ask. Stiles deflates. “Because Scott caught a whiff while I was mixing it and spent the next four hours in the bathroom.” Trauma: Stiles has it. “You use that vial, birth control or not, you’re going to end up pregnant. I’m saving it in case the alpha pack makes a comeback.” Stiles can just imagine it. One minute, terrifying alpha pack creeping all over Derek’s territory. Next minute, orgy.


Allison shakes her head. “No wonder Derek has been avoiding this room.”


Yeah, the kitchen probably needs to be fumigated. Stiles winces. Has he unwittingly been sexiling Derek in his own apartment when there’s not even actual sex happening? “I should apologize for taking over for so long.”


“He wouldn’t have given you a key if he didn’t like having you here.”


Stiles thinks that’s probably oversimplifying just a bit, but he can’t prove it.




After that, things more or less proceed as normal, except normal lately has included a lot more time socializing. They go on hunts. They have pack training. They hang out at Derek’s, at Stiles’s, at lacrosse games. Sometimes they even study together, and Lydia walks Stiles through the process of choosing a decent distance ed program.


Dad makes a face worthy of a sourwolf when Stiles tells him he can’t leave, and Derek gives him a look Stiles can’t quite parse, no surprise there. If he had to guess, he’d go with equal parts resigned and annoyed, and maybe just a tiny bit pleased.


But Stiles tries not to read too much into it.


Jackson and Lydia get back together. Stiles doesn’t even frown about it. That ship has sailed, seriously, and then it got lost at sea and went down all hands. Jackson even offers Stiles an awkward thanks for helping with the scent-faking thing, and they somehow start getting along, though Stiles still maintains it’s not friendship, more of a deep and abiding mutual regard born out of Hale pack puppy piles.


Halfway through October, Derek invites the pack over to the old house for a barbecue slash bonfire. Well, Stiles says “invites.” He means “sends a tersely worded text indicating they should all come over and that Bad Things will happen if they’re late.” But when they show up, it turns out to be a barbecue and bonfire—okay, so it’s actually an electric outdoor firepit, but nobody blames Derek for having issues—and not a supernatural emergency.


The really weird thing, though, is the house. Because sometime in the past few months (probably when Stiles was busy commandeering Derek’s apartment for fertility experiments), someone reframed the parts that were too badly burnt to be safe, knocked down some walls, redid the drywall, put in some new flooring, painted, redid the kitchen—


In short, Derek won’t be needing the apartment much longer. Which, considering that it’s now full of traumatic jerking off memories for several pack members, may be for the best.


When they’ve eaten so much steak and barbecue-toasted marshmallows that nobody can move comfortably anymore, and when Stiles has consumed enough liquid courage to storm the beach at Normandy, he looks over from his place on one of the picnic blankets and says quietly, “You could, you know.”


In the flickering light, he can just make out Derek’s throat working. “Could what?”


Stiles tries to keep his voice low, but he knows everyone but Lydia and Allison can hear him anyway. “You could meet someone. A girl. I.” He sighs heavily. “That stuff I made for Allison and Erica and Lydia, I mean. I made some for if you ever.” If you ever meet a woman and happen to mention that she seriously needs birth control, you could still have sex with her because I made you werewolf Viagra.


“Oh. That.” Derek closes his eyes like he’s in pain. Seriously, it hurts him when people are nice to him. Stiles’s heart breaks and his own eyes sting a little, because that’s not fair. It’s not fair that he hurts Derek when he tries to make things better. “I really can’t.”


Stiles clenches his hands into fists. “That’s bullshit. You shouldn’t—I know that you—” Okay, no, no matter how drunk he is, he is never going to mention his Kate Argent theory in front of the rest of the pack. He won’t do that. “That you feel responsible. Or whatever. But listen, Mr. I Can’t Have Nice Things, you don’t have to be alone. You don’t—stop punishing yourself. Please.”


And here’s the truth: Stiles is in love with Derek and has been for months.


He tries hard not to think about it, because yeah, Derek and most of Stiles’s friends are werewolves and they have super sniffers along with really good hearing, and that makes privacy kind of difficult. And Derek’s life is hard enough. He doesn’t need to add “object of barely legal son of the town sheriff’s affections” to his list of shit to feel guilty over. So he’s been hiding it as best he can, which, admittedly, is probably not very, but he can’t leave the pack because all his friends are here, and that means he can’t make it awkward.


And he really, really just wants Derek to be happy. To smile a little. To let Stiles help him, even kills Stiles inside.


When Derek speaks again, his voice is so low Stiles has to strain to hear it. “That’s not it. Werewolves… sometimes we meet someone and everything clicks. After we meet that someone, that’s it. With anyone else, we can’t even….”


Oh, Stiles thinks, and he’s too busy reeling to wonder if Derek can hear how that knocked the air out of his lungs. He swallows. “So you have a….” He can’t even say it.


Derek can, though. “Mate. Yeah.”


Nobody else around the campfire seems particularly surprised by this information. Which means they’ve known all along. “Is she….” He takes a deep breath, lets it out again. “Does she not want…?” In which case, seriously, what the hell. How can anyone not want Derek? Derek, who is damaged and hurting but not broken, who hides his courage behind false bravado and his affection behind empty threats of violence? Derek, who has done everything he could to make a family for people whose blood died, or let them down?  


Derek, who is so goddamn beautiful it’s hard to look at him sometimes. Like, being within a hundred feet of him gives Stiles a complex.


“It’s not a woman,” Derek finally says.




What?! “Oh,” Stiles says dumbly. “I mean, I thought—I apologize for the heteronormative assumption, but based on”—the Kate Argent Theory—“yeah, shutting up now. Okay.”


Then he realizes no one else around the firepit has so much as batted an eyelash at this revelation either. “Wait. Did everybody—they all knew your mate is a dude? And nobody told me?”


“Hey, Boyd, isn’t that show you like on TV tonight? Yeah, I think there’s a marathon.” Erica stands up, then drags Boyd after her. “Come on, if we hurry we’ll be in time for the second episode.”


“Oh, I love that show!” Isaac agrees. “Wait for me!”


“Oh, you mean the show with the thing? That show? That show is awesome!” Scott practically lifts a protesting Allison by her armpits. “I’ll make popcorn.”


“Someone with superhearing is definitely filling me in on this conversation later, because Derek doesn’t have a TV out here yet,” Lydia says archly, but nobody pays her any attention as they all swarm back into the house.


“We are going to have to work on their subtlety,” Stiles decides a few seconds after the patio door slides shut. Then he sighs. “So, okay, am I imagining things, or does the whole pack know who this guy is except me?”


He can practically hear Derek grinding his teeth. “They know. Not because I told them. They can… sense it.”


So that means they’ve met this person, probably. Once again, Stiles feels left out. He wishes he weren’t so firmly attached to his humanity, because sometimes being the only real mortal—Allison’s hunting skills and Lydia’s whatever mean they don’t count—sucks.


“Just, I don’t understand why you wouldn’t tell me. I mean, that was the whole point of the experiment, right? Okay, I admit to some degree of scientific curiosity, and it’s good that we’ll know if we meet any other alphas. I practically asked you about this flat-out. I thought we were friends. But you didn’t even tell me when you met the love of your freaking life.”


“That’s not—“ Derek starts, but Stiles is on a roll now and all token protests will be crushed under the steam of his monologue.


“Did you think I would judge you because it’s a guy? No, you have to know better than that. It’s not like you don’t know how stupidly attractive I find you, so clearly I’m not in a place to throw stones. Is it someone I don’t like? I could get over it, probably, I mean as long as he’s good to you. Unless it’s Jackson, in which case oh my God, but no, because then you’d be making the kicked puppy face every time you see him with Lydia, and you don’t. And you can’t have told him, because you spend all your time with the pack, you don’t have time for a boyfriend. A mate,” he corrects.


Derek squirms.


And actually—it can’t be a werewolf, can it? Because another werewolf would know. “So is that it? You didn’t tell me because—because whoever he is, he doesn’t know? Because you never….”


Derek’s looking at him.


Stiles’s mouth continues on without his brain. “Because you never told him about werewolves. About what it means for you. How can you, really, how can you expect someone to just be okay learning they’re your one and only? Not that I think that’s such a terrible thing, okay, it’s romantic in a very Grimm’s fairy tales way. But you’d never—”


He stops dead when his brain finally catches up. “You’d never tell someone that, because that’s too much pressure to put on someone, your happiness for the rest of your life. You’d do whatever you could to keep that a secret, you stupid self-sacrificing bastard. You’d just brood quietly and wait for the whole thing to blow over and for your fucking mate to move on to college and drop off your radar and oh holy God it’s me.” His pulse thunders in his ears, and he swallows convulsively. “Derek. Is it me?”


For a very long stretch, Derek doesn’t answer. And then he says, “Yes.” But it sounds forced, rough, and he’s staring into the faux flames again, not meeting Stiles’s gaze.


Stiles takes a stuttering breath, because he never thought—he never thought he’d be this close to this; Stiles never gets what he wants. He never thought he’d come this close and back down because—“But you don’t want me.”


Derek snaps his head around to look at Stiles. “I want you.”


Stiles shivers. “Prove it.”


And just like that Derek’s in his space, crawling forward until Stiles is lying propped up on his elbows with two hundred something pounds of werewolf straddling his body. Then he stops, his head tilted to one side, and Stiles can hear him sniffing, can tell by how still he is that he’s listening to the frantic pounding of Stiles’s heart. “You really—” he starts in a voice filled with way too much wonder.


“Oh my God, yes I really. Derek.” How does Derek not know this. He is so dumb. He is even dumber than Scott. “I thought you knew. I thought you had to know. Super senses ring a bell?” Also, why are they talking? They’re not even touching. Stiles is going to be a virgin forever.


Stiles can just make out Derek’s wince. “I can only read your body. Not… not your mind.”


Stiles is breath-catchingly sure Derek was going to say something else. “Well, my body definitely wants you. In, like, the most immediate sense possible, because I don’t think it’s capable of a whole lot of forethought on its own. Uh, and my—the rest of me is in agreement, and would like to add it is completely on board with the whole ’til death do us part thing.” Wow, okay, his brain has been taking creepy lessons from Derek apparently, because way to overshare, but at least that was the truth. “But only if it involves you actually kissing me in the next thirty seconds, you enormous tease.”


Derek makes a sound that might be a laugh, and Stiles has to suppress a bittersweet pang, because he got to hear it but he didn’t get to see it happen, didn’t get to watch his face, really, because it’s too dark and he’s too close and Stiles has closed his eyes.


Then Derek kisses him, and he forgets to be upset.


“How long have you known?” Stiles asks a few minutes later, when he’s trying furiously to distract himself from still being a virgin while also being hard enough to pound fence posts with his dick.


When Derek answers, his chest vibrates under Stiles. Which is not helping with item B above. “How long have I…? Or how long did I know I was your mate?”


Of course Derek can’t use feeling words, Stiles thinks. Right now that just makes him feel kind of warm and fuzzy, but it’ll probably be really annoying later. Stiles will have to train him. “Both.”


“The first thing”—oh my God, seriously, talking around I knew I liked you when is so awkward, why does he even try—“when you dragged your half-paralyzed body through a building to find your dad.”


That’s—yeah. That makes sense. Family, right?


“The second thing….”


Stiles can tell from his voice that this is going to be an embarrassing story for at least one of them. He hopes it’s Derek, but fuck it, if it’s him, he can live with it. He is basically using Derek as his personal mattress right now. His ego can handle anything. “Come on, spill.”


Derek huffs and nudges Stiles up so he can shove his face in his neck. They’ve been together five minutes and Stiles already knows this is going to be a thing.


“During your experiments for Scott,” he admits like someone’s tearing the words out of him. “Let’s just say the smells combining in the kitchen made me want to commit violence upon Scott’s person. More than normal.”


Stiles almost whistles. That’s a serious amount of violence.


“And then you got some of my, uh, scent on you, and—”


Wait a minute. No he didn’t. Stiles was super careful about that.


“What? You went tense.”


“I definitely didn’t get any on me,” Stiles tells him firmly. He thought about it, but that was too manipulative for him. “I was really careful, I used a new set of gloves for each—” And then it hits him. “Oh my God, Lydia is a terror.”


Feeling Derek’s startled laughter almost makes up for not being able to see his face.


It makes Stiles bold. “You know, if you liked that, we could recreate the circumstances of that experiment.”


Derek flips him over so fast he doesn’t even have time to be winded, and presses his ridiculous body against Stiles’s. “I guess we could do that,” he says playfully. “For science.”