Will eventually also go on ao3
They don’t talk about it.
Which is crazy, Stiles has never not talked about anything in his life.
But he can tell Derek feels weird about it. Angles it away from Stiles when it bumps against Stiles’ rim. Takes off the condom and makes a show of it, like Stiles can’t feel it, incessant. In the heat of the moment it’s hard to talk about. It obsesses him.
But still he can't bring it up first. That's pushy, and pushy is the last thing Stiles wants to be about their sex life. He knows Derek probably feels weird about it. Maybe it's a rule or something, you're not supposed to knot a human.
He tries to look it up, sees some pretty interesting porn, but nothing about a full on taboo. On the contrary, the few places he feels have good information about were-human relationships seem to mention it here and there but not in a way that strikes Stiles as particularly taboo.
Derek, as always, is different.
And Stiles can do without it, of course he can.
The only problem is wanting to talk about it.
Derek lands next to him, bed bouncing a little, and he pulls Stiles closer. Light streams through the large windows of the loft and down onto Stiles’ bare body, now covered in evidence that Derek is different.
He scoots closer, and he can feel it against his hip, and Derek hisses and jerks, coming more.
Stiles blinks blearily. “Sorry. I’know you don’ like me to touch you.”
Derek’s brow furrows. “What?”
“I mean… your knot,” Stiles’ voice is slow, still clogged with moans.
“Again, what are you talking about, Stiles?”
Stiles is coming online slowly, but not fast enough to shut himself up. “You don’ wanna knot me, or want me to touch it. ‘M saying I didn’t mean to do that.”
Derek’s nostrils flare, but he says nothing.
And that sits like a rock in Stiles’ stomach. Maybe he wasn’t supposed to notice.
“Sorry. I don’t know your rules.” Stiles says, hoping the afterglow softens whatever hard edges he dug into his boyfriend.
“You can touch it.” Derek says, but he doesn’t move.
Stiles stifles a sigh. “Well, don’t sound too excited about it.”
He goes to pull away, go clean up, gather up his own jagged edges, but an iron grip around his waist won’t let him.
He glances up, speared again by Derek’s beauty. The light shows the bronze in his hair, the silver in his eyes, and paints his skin gold, and he looks at Stiles with supreme concentration.
Stiles blinks a few times, and then slowly steals his hand down Derek’s chest, glancing off smooth skin.
Derek kisses him as Stiles’ fingers finally reach around his cock, around the smooth skin of the knot. He’s still rock hard, and Stiles’ gasps, not sure what he was expecting. Derek is hard and he’s coming more. Stiles shivers, squeezing more than he is stroking, working off of what he gathered off the forums and also off of whatever makes Derek’s breath catch.
He explores, tugging and squeezing, groping Derek’s balls with gentle hands. It’s so smooth, the skin velvety and lubed already, and Stiles is fascinated. He wants to go further. He wants to research.
It seems to go on endlessly, the golden light, the heady, glorious taste of Derek, the smell of him, painted all over Stiles’ skin. Stiles’ hand starts to cramp but he keeps going, feeding off of Derek’s pleasure like a man starved.
Derek groans, breaking away and resting his forehead against Stiles’.
“I’ve never,” he gasps. “With anyone but you. Didn’t wanna- god, fuck, Stiles, fuck, your hand, fuck, FUCK.”
He gasps into Stiles’ mouth and spurts one last time over Stiles’ belly.
They stay like this for a long moment, breathing nearly into each others’ mouths to the point that Stiles genuinely thinks about carbon monoxide poisoning.
“I’ve never… with anyone but you. Didn’t wanna do it wrong, hurt you, or freak you out.”
Stiles curls closer, hiding his face in Derek’s throat. “Well, I did freak out. Just a little.”
“I don’t know how to do it,” Derek says simply. “Can’t take chances with things like that.”
Stiles swallows. “I know of some forums. And some porn.”
Derek’s throat works and then he laughs, the rich sound pouring through Stiles like honey, soothing every small hurt.
“Pun intended?” Stiles asks.
Derek chuckles and turns his head to kiss Stiles’ cheek.