Stiles comes harder than he ever has in his whole short life. It feels like he's being turned inside out, and he wails like a wounded animal as he shoots spurt after spurt of gooey jizz all over Derek's amazing chest, where it travels in zig-zaggy rivulets through the hairs there. It's beautiful, is what it is, though considering the sheer high of orgasm that Stiles is floating on now he'd probably call anything beautiful. But especially Derek, holy crap he's the most beautiful thing in the world right now, sitting up against the headboard. Beautiful with his frowny eyebrows and his chiseled jawline and his amazing mouth, the corners of which are... turned down? That's not right.
"What-" Stiles pants, and gulps down a few more breaths before he manages a full sentence. "What's with the face?"
He's pretty damn sure it's not because Derek didn't come, because Stiles has never felt this full in his life, and it's decidedly squelchy where he's sitting, thighs still shaking from exertion and pleasure. He'd given Derek one hell of a ride, and it had all been worth it. Every second, hot damn.
But Derek doesn't seem to want to meet his eyes, and the hands that were clenched so wonderfully tight on Stiles' hips only moments ago are now hesitant in their touch, as if expecting Stiles to refuse them. Like he would, holy shit, Derek's grabby werewolf hands are always welcome on Stiles' anything.
"Hey," he tries again, softer, ducking his head to try and convince Derek to meet his eyes. "What's wrong? Did I do something?"
This makes Derek look at him, finally, incredulous. "Did you- you don't feel that?"
In way of reply, Derek thrusts up again, gently, and Stiles gasps. Oh, that's good. Very, very good.
"Oh, wow, someone's got a quick refractory period today," he purrs, and drapes his arms around Derek's neck. "I'm all for it, but my dick needs a minute."
"It's gonna get like twenty," Derek mumbles, eyes averted again.
Derek gives him a weird look, and then sets his jaw like he does when he's expecting something really unpleasant or hurtful. Stiles would ask, but before he can, Derek's hands tighten, and he lifts Stiles off his lap. Or, rather, he tries, because barely half an inch later there's a painful pull of something way too big trying to get past the rim of his ass, and he's pathetically grateful when Derek just gently lowers him back down.
"Feel it now?" Derek asks miserably, and Stiles stares at him.
"Well, yeah, I felt that before, but I just thought you shot the most spectacular load, and had zero refractory time!" It takes a moment to put the pieces together, but Stiles still doesn't get why Derek looks like his pet bunny died.
"Okay. Okay, so you have a knot. I did not know this. But, okay. It was unexpected, but everything's cool, no one got hurt. So why the face? Is something bad gonna happen? Are we werewolf married now or something?"
Derek's eyes whip up to meet his again. "No! No, it's just... I didn't mean for it to happen."
"So? I didn't mean to come in your eye that one time, shit happens. And, sure, it's a little inconvenient, but I just had, like, the most fantastic orgasm of my life, here, dude, so I'm kinda struggling to see a downside?"
It takes a long time for Derek to answer, and seeing as he evidently won't be going anywhere in the immediate future, Stiles just waits patiently.
"It's... only supposed to happen with... someone you care about. A lot."
That's not much help, honestly. "So? I mean, we haven't exactly had dramatic near-death love-confessions or anything here, but we're... caring. About each other. Right?"
"Right," Derek says flatly, and Stiles rolls his eyes.
"Do you need to hear me say the words? Cause I will, if that's what it takes to wipe that downer off your face."
There's a pause, as if Derek's considering it. "No. No, it's... you should only say it if you want to. Not for my sake."
Stiles is well-versed enough in Derek-speak now to know that that means he won't believe it if Stiles says it now, so while he was totally ready to declare the thing that has so far only been labeled just that - The Thing - in his head for months, it can't be now. Derek will assume it was only for some weird self-sacrificing reason, because Derek has issues the size of Texas.
But if nothing else this exchange proves that Derek does seem aware of the level of affection between them, and they're not magically soul-bonded or anything, and Stiles is still feeling pretty damn good, his dick valiantly plumping up for round two already. So why does Derek still look so damn sad?
"Then what?" Stiles prompts, and then kinda regrets it when Derek's jaw ticks. Oh boy. He already knows what's coming.
Stiles fucking knew it. That shit stain that called itself a human, but definitely never ever deserved the title, always makes Stiles fume with rage, but he keeps a lid on it, because if Derek is actually uttering her name, shit must be serious.
"I... once. With her. Because I... and she.... she laughed."
If Stiles hadn't been so full of good feelings and orgasm floatiness before this he would have puked. Derek doesn't even need to form complete sentences, and it's obvious what happened. Derek loved her. Stiles knows this, and he will never ever blame Derek for following his heart. But that evil meat bag took one look at this proof of tender feelings, and fucking laughed at it. Stiles wants to bring her back to life so he can kill her all over again.
"Derek. That was her being a monster. You know that, right?"
Derek doesn't nod, but Stiles doesn't expect him to. These things don't go away overnight, or even over decades.
"But more importantly, right now... do you hear me laughing?"
There's a tiny head shake, and that's progress.
"Actually... didn't you see me all blissed out a few minutes ago?"
"So... logic would suggest that I'm perfectly happy with this. Right?"
Derek's eyes dart to his, briefly, though he must have already listened for a lie in Stiles' heartbeat, and found none.
"Then why don't we just enjoy it, hm?" It might be a cheap trick, but he grinds down carefully, definitely feeling the bulge now that he knows it's there, though not nearly as huge as he would have expected, had he even considered before now that Derek might have one.
Derek gasps, and digs his fingers into Stiles' hips, which makes him stop. He has to make sure Derek is game, or it'll be Bad. Capital B Bad.
"If you don't want to, it's fine, we'll just chill here for a-"
That's how far as he gets before Derek yanks him in for a kiss, all tongue and hunger and yearning. It makes Stiles' heart hurt a little bit to think that Derek might have forced himself to hold back out of fear, when literally nothing could ever make Stiles turn him away. So he kisses back, with everything he has, feeling his cock start to drip pre-come again, because kissing Derek will never not get him excited.
He's apparently not alone in that sentiment, thank God, and he whimpers when Derek thrusts up again, lifting Stiles, and literally mashing against his already sensitive prostate.
"Yeah," he sighs against Derek's lips. "Fuck yeah. Does it feel good for you too?"
Derek nods, eyes going slightly glassy as he thrusts again. "So good. Stiles, you have no idea."
"I think I might, though. Unh! Oh my God!"
Stiles feels almost like crying when he catches a hint of the smug, wolfish grin Derek only sports when he's feeling really proud of himself, because Derek deserves all the smug sex in the world. But that doesn't mean Stiles won't fight back, dirty and hard, and he clenches down on the firm bulge as forcefully as he can, grinning himself when Derek moans and shudders.
"Show me what you got, then, big guy," Stiles taunts with a smile, and Derek smiles back, eyes glittering with challenge, and hands clenching tight on his hips again. This is gonna be the best sex ever.