The first time it happens, he’s on his knees, Peter’s cock hitting the back of his throat, and he doesn’t really realize what happened until later--doesn’t put it together as it happens but later, when he’s alone and stripping his cock to the memory of the older man groaning when he rolled Peter’s balls between his long fingers, when he thinks about the way he had jolted when Stiles ran those same fingers along his taint, and brushed against his tight hole, the way he’d come with a strangled moan when Stiles pressed --
Stiles comes with a gasp, spills hot and white over his belly and blinks through the aftershocks.
“Holy fuck,” he whispers.
He doesn’t bring it up.
Not terribly strange. Whatever it is they’re doing, they don’t talk about it, much. It happens regularly enough that he knows it’s serious. There was, too, the way Peter got too still when a college buddy hit on Stiles, the way the gleam in his eyes went just a little manic, reminded Stiles of the psychotic murdering alpha that he helped kill.
So. They don’t talk about the fact that they’re fucking, but it’s there, a serious relationship that defines his life, that the pack has accepted--Derek with a searching stare, Scott with snarling reluctance, Lydia with a icy threat--but no one talks about it, just like no one talks about the fact that their freshman year of college Derek tried dating again, even got serious about the guy, before the pack realized he was a incubus with a higher body count than even Jennifer Blake.
The pack is good about not talking about things, and this--this is one of them that Stiles files away.
But he doesn’t forget.
One of the things Peter loves about him is his quick clever mind, and he knows he’s right. So he waits, until a few weeks later when Peter is fucking his face, his hands clenched on Peter’s ass, and he lets his finger brush against the older man’s hole, lightly.
Peter jerks like he’s been shocked, his eyes flaring electric blue as his control slips.
When Stiles presses in , Peter snarls and comes, his knot beginning to swell in the wet heat of Stiles’ mouth before he jerks back, and finishes coming on Stiles’ face.
And well. That might not be three for a pattern, but the way his boyfriend is twitching and sated on their bed is all Stiles needs to know.
Peter is lying on their bed, naked because he’s a shameless exhibitionist, when Stiles comes home.
He smiles as he presses a kiss to the older man’s shoulder, and then goes to the bathroom to shower before he crawls into bed behind Peter, nestling against him and listening to him breath.
“Read to me,” Stiles murmurs and Peter gives a huff, but he does, his voice rich and soothing even as he reads about faery mating habits.
Stiles runs his fingers, idle and absent, over Peter’s skin as he listens, presses kisses into the curve of his shoulder almost as an afterthought.
Until his fingers sweep over the curve of Peter’s ass and the older man shivers, his even voice hitching, just a little.
Stiles pauses, and then rocks forward.
Peter’s cadance stumbles, but he doesn’t acknowledge Stiles.
He lets his hand brush down, over his ass, and Peter rolls with the motion, onto his stomach as he continues reading and Stiles rubs his thumb over his hole.
Peter gives a full body shudder that Stiles can feel down to his toes, and he pulls back for a moment, reaching for the lube while Peter reads and wiggles impatiently.
He takes a moment to position himself behind his boyfriend, to enjoy the view.
They’ve been fucking for months, now, long enough that John doesn’t even glare at Peter anymore, and he’s never had this.
Peter is generous and devoted, and their sex life is active enough that sometimes Scott complains--but Stiles likes being fucked, and Peter has never voiced the desire to change things up.
This though--this is something he didn’t realize he wanted, until Peter stretched naked and gorgeous and his for the taking. His tight little hole is pink and perfect and Stiles gives in to the impulse to lick over him.
Peter’s voice breaks off, his whole body going tight before he almost shoves his ass back at Stiles.
“Stay still for me, baby,” Stiles whispers and then licks him again, a slow drag over his hole before he sucks at it, his tongue dipping into the wet curl. It’s tight and hot and Stiles has to wiggle his tongue a little, licking sloppy and fast until Peter’s hole loosens and he lets out a little whine, needy and sweet as Stiles’ tongue sinks into him.
He stays there for what feels like hours, alternating between fucking his tongue deep into Peter and licking over his wet loose hole, licking down his taint to the underside of his balls, until Peter was practically sobbing with it.
When he finally pulls back, Peter does sob, a desperate catch of Stiles’ name and then he screams as Stiles slides his fingers deep, two fingers thrusting deep and Stiles groans, lets the noise mix with Peter’s as he fucks into his boyfriend’s tight ass.
“God, baby, you--”
“More,” Peter gasps, begs, “Stiles, more!”
Stiles snarls a curse and adds a third finger, his heart catching as Peter hisses and rocks back, trying to take more, fucking himself now.
“Shoulda told me,” he mutters. “God, look at you, you’re so fucking needy for it. Needed this, needed to be filled up, huh, baby?”
Peter gasps and shudders, and Stiles sees the way his shoulders tremble, the flush on his neck that he always gets right after he comes and he rips his hand free, ignoring Peter’s desperate wail as he slicks his cock and then--
Stiles knows Peter’s making noise, and he wants to hear them, wants to hear his boyfriend’s beautiful noises, but all he can hear is the blood rushing in his ears and the squelching sound of of fucking into Peter’s ass.
He moans, hands gripping Peter’s hips, as he buries himself to the hilt in one stroke, and stays there, shaking as he slumps over Peter’s body. It takes a minute for anything to penetrate the fog of sensation, the vise grip on his cock, the familiar silky skin of Peter’s ass pressed to his groin, the way Peter shook beneath him. But when it does, he can hear Peter, crooning, soft and familiar. “So good. Knew you’d be good, knew you’d fuck me so sweet. Please, sweetheart, please, need you to fuck me.”
Stiles whimpers and twitches and Peter groans, a loop of sensation.
“Stay still,” Stiles grits out, a hand on the nape of the werewolf’s neck and Peter goes boneless, slumping into the bed, his ass up and Stiles--
Stiles loses it.
He wants to take his time, fuck Peter slow and good, rock his world the way Peter so often rocks his, and he can’t --he fucks him hard and fast, a goddamn sprint to the climax, gritting curses, and fingers digging bruises into his skin and Peter just takes it , face slack, eyes closed, grunts punched out every time Stiles hits his prostate, and it’s that--the way Peter , egotistical, power hungry, devious and brilliant Peter , lays there and let’s Stiles has this, gives Stiles this , his throat bare and vulnerable, his defenses completely forgotten--
Stiles comes with a strangled shout and Peter shoves back on his dick as he does, a high whine in his throat as he shudders and groans. Stiles fumbles for him and--
“Peter,” he gasps, and Peter laughs, broken and sated, shuddering through the extended orgasm he always has when he knots.
His knot, red and swollen for nothing, because Stiles fucked him. Stiles rolls his boyfriend with a huff, shoving three fingers in his empty hole and says, “After this, I’m eating you out again--you’re all messy.”
Peter’s claws sink deep into bed, and he curses as Stiles swallows him down mid-orgasm, his free hand clenched around the swollen, angry knot.
They don’t talk about it. And Peter fucks him, more than anything else. He likes being fucked, likes the feeling of being full and covered and safe, likes Peter’s hand holding him open after, as he licks Stiles clean.
So they don’t talk about it and it doesn’t change much.
But sometimes--he comes home, and Peter is naked in their bed, and his eyes gleam hungry and needy.
And Stiles smiles.