Seeing twenty four year old Derek smile is... Terrifying, pretty much. He has only witnessed such a thing a handful of times, and it always feels a little weird. Like the smiles get torn straight out of Derek's soul in a hurtful way.

Fifteen year old Derek does it all the time, though, with surprising ease. His clean shaven, smooth looking face looks amazingly open when he does it. That alone is enough to break Stiles' brain forever. Pretty much everything else, he can take. But a Derek whose lips and other varied face muscles can bend, stretch, and contract that way without splitting something? That's something else entirely.

"So, Stiles, right? I've never seen you around, where have you been hiding?" Just like that there's a thirty bajillion and sixty thousand watts smile being thrown at him. Like those on magazines and tv shows, like those ones movie stars sport. Woah.

Aaaaaand a wink. Yes, that was a wink. An honest to God lecherous borderline creepy wink. Another thing that blows Stiles' brain up with the sudden force of a molotov.

He turns away from the kid (the *kid*, Derek's now a *kid*, just *how* is this his life, he won't ever stop asking that to himself, it won't ever ever grow old) that's, uh, possibly trying to get into his pants with the worst pick up lines and less smooth moves ever (including his, and you should hear some of the things he's said over the years on his quest to get Lydia's attention), and faces Scott.

"Scott, dude, don't know what you did or how you did it, but I think you've damaged Derek beyond repair. Screwed with him big, big time."

"Hey, it wasn't me! I didn't know there were real witches in the for- Hey, hands off, buddy!"

Stiles turns around to find that little Derek is reaching out to touch what would've been the back of his nape if he hadn't turned. Him turning around means that the tips of little Derek's fingers are casually touching his lips. Or not so casually.

That is a rampant 'yes' to the question of whether or not he's trying to get into his pants, then.

"Dude, boundaries." Says Stiles, grabbing the kid's hand and waving it around frantically. "Start working on them. Being a werewolf is not a good excuse to be all up in my grill."

The look on Derek would be hilarious if the situation wasn't so entirely screwed up; his eyes look big, wet and innocent, his mouth is slightly parted, and there's a little of a flush going at the top of his cheekbones.

And then Stiles' words seem to hit home and his eyes widen even more, and he's very clearly afraid and on the defensive.

"You-, werewolves are not-, I'm not a-," He stutters, looking lost and a little frantic, probably closer to wolfing out by the minute. Stiles puts him out of his misery to avoid a throw down between him and Scott.

"Derek, dude, calm down. Scott here?" He points at Scott, who is torn between looking put out, stern, and a little amused. "Is a wolf, too. Rawr rawr, claws and teeth and the whole shebang." Derek relaxes a bit, and Stiles just has to ask, "shouldn't you be able to smell him or something?"

Derek actually blushes at that. Blushes so hard that Stiles can feel all the heat radiating from him, like a little werewolf furnace. Also, the resemblance to their Derek comes back when the guy snarls at them.

"I've just started my training, okay." Then he stops and asks them, "Wait, how do you know me? Are you pack?" He scents the air, and Stiles is really fucking glad that all this is happening in his room where noone can point out how freaking weird all of them are. "You smell like pack, but..." He trails off, locks eyes with Scott for a few seconds. Then asks, voice gone steel hard and the closer to older Derek that it's gone to, so far. "What happened to my pack?"

It suddenly hits Stiles like a train. Of course this Derek laughs all the fucking time, and of course he's somewhat more outgoing and cheesy and a little bratty. This is a Derek that still has a family.

A Derek that *thinks* he has it. That had it at the time he was trully fifteen. How are they expected to tell him that he's the only one left? That everyone else's been killed? It's not fucking fair.

Stiles fucking hates witches.

Derek cries when they break it down to him. He sits down on Stiles' bed, put his head in his hands (claws out and digging into his skin, drawing a few droplets of blood from his temples and the top of his forehead), and bawls. Stays like that, curled in on himself, for an hour; sobs wrecking him and tearing Stiles' heart in two.

Stiles fucking hates witches so fucking much. And he fucking hates Kate, and Peter, too.

"You two," Says Derek, voice soft. "Are you two the only ones left?"

"There's Jackson and Lydia, too." Scott offers, from his place on Stiles' window. Stiles can tell that he wants to do something to appease Derek's grief but knows there's nothing else he can do other than this, "They are new, too. You sired Jackson."

"Okay." Derek agrees, in a subdued manner. "I don't think I'm ready to meet them." A few seconds later, he adds, "I was never meant to be an Alpha, y'know?"

Stiles goes to sit next to him and hugs him with one arm, as Derek plasters himself to his side, brings his hands to Stiles' arm and starts sobbing again, head on Stiles' shoulder.

Scott looks at him with an emotion that Stiles can't quite place, but when he mouths 'what?' at him, Scott just shakes his head and mouths back, 'nothing'; the foreign look stays there.

He ignores it, for the most part, letting Derek cling to him.

Scott's got to leave for his part time job at the vet's, eventually. He only does it after Stiles assures him repeatedly that they'll be okay; Scott gets that unreadable expression once again, but nods and leaves them alone.

Derek is still sitting on his bed, but he's not looking as miserable. He is mostly looking at Stiles' room while Stiles tries to look for a way to reverse the spell.

"You're kind of a geek."

Okay, yes, the kid's feeling definitely better, if the entertained (and fond, but he's not going there, because that way lies madness) tone of his voice is anything to go by.

"And you are a self important ass, but you don't see me throwing it in your face." He lets out, indignantly.

"You just did." Retorts Derek, in a warm voice.

And Stiles squeaks in the least manly way ever and almost falls off of his chair in his haste to put some distance between them, because suddenly Derek is right there, talking next to his ear in a soft, warm voice.

"Holly shit, Der- what did I tell you about boundaries, buddy?"

Derek just smiles at him, resting his hands upon the chair handles, trapping him there. Stiles can see a playful albeit predatory glint in his eyes, along with a small speck of sadness that he doesn't think will go away any time soon.

"You are different from Scott, aren't you?" He asks, breathy and low. Inching closer and closer to Stiles, who doesn't have any more room to escape.

And isn't sure if he wants to, in all terrifying honesty.

Because the thing about young Derek is that he's just as hot as regular Derek. Slightly less muscular, but still nicely built; also, young Derek has a disarmingly naïve air around him that Stiles finds incredibly alluring.

But more than anything else? He's just *Derek*; he's got that same musky scent that's impossible to ignore from such a close distance; he's still a cocky bastard; he's still Derek, and Stiles is pathetic and not good at denying how much that alone undoes him, leaves him lovelorn, stupid.

"Yes, I'm different from Scott," He answers, rushed. "Not a werewolf. I'm sort of the token human."

Derek smirks at him, his face so close that his breath hits Stiles' nose, lips, cheeks.

"That's not what I meant. Also, it's complete bullshit. I'm fifteen, not an idiot." He brushes his nose against Stiles' cheek, and he congratulates himself for not jumping to the fucking ceiling.

"I really don't know what you're talking about, dude. Also, if you could maybe let me up? This is getting werewolves-being-nice levels of weird."

Derek bumps his nose against Stiles' right cheekbone, then he lowers his face to the juncture between Stiles' neck and shoulder and takes a deep breath. The sound that he makes (half whine, half moan) makes Stiles' own breathing hitch.

*Fifteen*, he thinks. This Derek is currently *fifteen*; Stiles is only two years older, but it feels like it should be a huge huge, insurmountable gap. It should make him want to make Derek stop. He can't think of anything else that's big enough to make him make Derek stop.

"You smell so much more mine than Scott," Derek says, mouth opening and closing against his throat, "you smell like mate." He concludes. "You smell so good, so so good. Have we done it yet? I don't know how to smell that, yet." He waits a second with his lips parted against Stiles' skin before saiying, all rough, "Tell me we have."

Stiles is left speechless, at that. He doesn't know whether he is more confused or intrigued or turned on or ashamed.

"Please tell me we can do it now." Derek begs, equal parts horny teenager and needy desperate wolf.

There's that only thing big enough to make him want to stop Derek.

"We won't have sex to alleviate your pain." He says, moving his hand to Derek's shoulder, to try and make him budge. "It won't make you feel better, it won't make anything that's happened less real."

There's a frightening long silence after that, and he thinks that maybe that was too much, pushing too far, that maybe he fucked up and little Derek will wolf out and eat him, or-

"Okay." Derek sounds deflated against him. "Okay, you're right. Don't... Don't freak out, okay?" He moves a little and presses a kiss against Stiles' right clavicle, dragging down his shirt a little bit. "Just, just give me a minute. Like this."

Stiles doesn't understand (doesn't want to understand), but makes an affirmative noise.

An hour after that or so, Scott sends him a text saiying that he's really sorry and that he can't come back right away because his mom's home for the night and wants them to spend some time together, to bond or something. Says he'll try to sneak out when she goes to bed.

Stiles texts him back to not sweat it, to enjoy his mom and sleep. That Derek and him will be okay for the night.

Derek spends the night in Stiles' bed, burrowed under the covers, clutching them with white knuckles, squeezed against his nose, and slipping a little between parted lips. He looks so young that it makes him ache.

Stiles spends most of the night looking for a solution to this big ugly mess.

And finds none.

At some point around four or five o'clock he gives up for the night and collapses on the meager free space on his bed, closing his eyes and making himself as comfortable as he can.

"Tomorrow we'll find a way to fix this, Derek." He tells the sleeping boy lying next to him. "A way to get you back to normal."

He drifts off in a matter of seconds, falling into dreams of their older Derek looking at him with blazing red eyes, grabbing him and pushing him against walls and saiying "you smell like mate", acting on it.

When he wakes up, his first thought is 'man, is my neck even supposed to bend like this?'. His second thought is that his bed's shrunk overnight.

The third one is that Derek's stubble will irritate the hell out of his cheek's skin-

Oh.

He opens his eyes to look at Derek, who is barely a few inches away from him, apparently twenty four again and awake and looking at him with a hunger that weakens Stiles' limbs.

"I thought I'd told you about boundaries." He says, smiling.

"You did." Answers Derek, smirking, and proceeds to lift himself on one of his elbows before going for his mouth.

The kiss is all tongues running through the inside of cheeks and teeth nibbling lower lips; all Stiles' inexperience and Derek's need to assert something that Stiles' doesn't entirely get, and a shitload of feelings that both of them had hid and are now leaking all over each other.

For a first kiss it's pretty epic.

When Stiles meets Scott the next day, the other teen wrinkles his nose and says,

"You reek of our Derek." The vaguely traumatised look on his face makes Stiles' want to mock him mercilessly, "I want to be glad that he's back, dude, but I am also picking up on way more than I ever wanted to know about your sex life."

He grabs a book from his locker and says, heartily, "I fucking hate witches."

Stiles, even when he agrees with his entire soul, can't help but laugh.