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"Okay," Steve says, shifting on the pillow to bracket Tony's slumbering head with his thighs. His cock is already hard and throbbing, ready to slide into Tony's mouth when he awakes. Tony's lying on his front, his languorous body rocking infinitesimally as Bucky fucks him so painstakingly slowly that he's nowhere near waking up.
Bucky's never woken Tony—not once in all the months they've been doing this. Bucky's perfected the slow and steady art of making Tony come in his sleep, of getting off in Tony's body before leaving the butt plug he removed on the empty pillow beside Tony's and silently going back down to his floor.
But tonight is different. Tonight's the big reveal.
Steve nods at Bucky. "Wake him up."
Bucky shoots Steve a wolfish grin from over Tony's pert apple bottom, slides Tony's legs apart, gets his knees between them, rucks up Tony's hip with his flesh hand, and ramps up the intensity of his thrusts, speeding faster and faster until Steve motions him to maintain. That's good for now: fast and rough for a baseline human, but far from the most a super soldier can dish out. Steve doesn't want Tony to know who's fucking him just yet—that's why Bucky's metal fist is buried in the sheets.
Tony's unconscious undulations in time with Bucky's slow, deep thrusts swiftly go jagged. The harsh slapping sound of Bucky's hips and balls pounding Tony's ass sends tingles down Steve's dick. Steve grips it in a ruthless fist as it grows impossibly harder, and drinks in Tony's confused yelp and half-whines as his body crashes from slumberous pleasure to rudely awakened.
Tony flounders, flails. Steve lets him paw around the bed long enough to realize Steve isn't where he should be, then presses Tony's wrists to the mattress with his feet—close enough that he can see Tony's hands without turning his head, and carefully leaving them enough range of motion for Tony to signal his safeword if he so chooses. Then Steve drags his boyfriend's head up by his soft, sleep-mussed hair. He smirks when Tony notices the hard cock so conveniently close to his mouth, but tugs further to prompt Tony's pretty brown eyes up to meet his.
He watches the realization wash over his boyfriend's face that Steve isn't the one fucking him—that it's someone else, someone not Steve, an anonymous stranger. Tony's eyes widen, then clench shut, and he moans loud and long, pushes his ass back onto Bucky's cock in a sinuous move Steve is deliciously, intimately familiar with. He watches Bucky's toes curl and pets Tony proudly, proprietarily. Bucky clamps his metal hand over his own mouth to stifle his pleasured groans—and, no doubt, the sweet talk Steve's learned to expect from him after so many months bringing him in late at night to indulge Tony's somnophilia kink and desire to be used by a mystery person of Steve's choosing.
This will be the last night of their arrangement. Steve and Tony asked Bucky out a week ago, and he promised an answer when he returned from his mission with Nat and Clint. Tony doesn't know he's back yet. Tony does know that if Bucky says yes, tonight is his last night to enjoy his 'used by a stranger in my sleep' fantasy; Bucky stated outright that if he dates them he expects exclusivity. Even if he hadn't, however, Steve's never really been comfortable with letting anyone but Bucky fuck his boyfriend.
Not that he's ever told Tony that. If he had, it would've ruined the mystery element of Tony's fantasy.
He knows part of Tony's fun tonight will be finding out who's been fucking him all these months, but now is too early for the reveal. Tony explained what it is he wants from this final encounter during their negotiations. His eyes had lit up and his breath quickened when he talked about knowing he was being fucked by God knows who—like Steve owned him and chose to lend him out because he could. He'd wanted the thrill of helplessness, the illusion of being powerless to stop the man Steve brought in from using him. And he'd asked Steve to draw out his anticipation, make him wait to find out whose come he sometimes woke up to find flaking on his thighs or dripping from his ass when he sat up—the come of the mystery man relentlessly fucking him now.
So Steve keeps a tight grip on Tony's hair—warning, controlling—when Tony tries to whip around to see who's pounding him so hard his plump, perfect ass is jiggling along with the bed.
"'Bout time you woke up," Steve says sternly. He shifts his hand down to raise Tony's chin, gazes assessingly at Tony's desperate eyes and the pleasured grimace twisting his lips and furrowing his brow. Finally, he nods at Bucky across his boyfriend's muscular golden back. "You can go faster now. Hard as you want." Then, fairly cooing at Tony, he adds, "You can take it, can't you, baby?"
"Yeah, yes," Tony whines, frantic voice choppy with the punch of Bucky's thrusts. "I can— F-fuck! Can take it— Please, please, I need— Steve, who—?"
"Don't pretend you care who it is," Steve cuts in, a hint of mocking in his fond tone. "You're just glad there's a cock filling you up, aren't you, sweetheart?" He strokes a teasing thumb across Tony's plush lower lip, nudges the tip inside. "Open for me."
Tony's instant obedience sends a rush of warmth through Steve's core even before he slips his cock into Tony's waiting mouth with a contented sigh, pushes slowly but unceasingly until the head hits the back of Tony's throat, and Tony's cute nose is nestled in Steve's neat, wiry blond curls. Tony swallows and swallows, and mostly holds still. Steve can see he's trying hard to be good, and can't fault him for the way his nose bumps into Steve's skin when Bucky's hard thrusts shove him forward, before he's roughly jerked back again to re-wet Bucky's dick. It's with Steve's usual fascinated awe that he lightly strokes his own cock through Tony's fragile throat and watches his eyes tear up. Steve waits for drool to drip onto his hand and Tony's face to turn red before pulling out far enough for Tony to catch his breath. Then he pushes right back in.
"God, Tony," he groans when Tony sucks as Steve pulls out, teasing his tongue along what he can reach. "You're such a good little cocksucker," Steve says, as much because it's true as to watch Tony's eyelashes flutter, feel him shiver and preen around Steve's dick. "You look so pretty with your slutty holes stuffed full of cock, baby."
Tony keens and looks up at Steve with wet, luminous eyes.
Steve glances at Bucky and grins smugly at the mounting desperation on his ruddy face. "I know our friend here thinks you're pretty. Just the sweetest, prettiest cocksleeve he's ever had."
Tony writhes and moans. Steve revels in the reverberations around his cock, revels still more when he pushes in just far enough to cut the sound off with Tony's breath.
Tony's eyes are glazed over, his body trembling and pliant, when Bucky gets that curl in his upper lip that means he's close. His rhythm speeds up impossibly, and he tugs Tony's hip hard enough that Steve sees marks start to form. That's Tony's favorite place to find bruises.
Steve pulls out of Tony's mouth, prompting a whine from Tony that he shushes absently by stroking his hair and sliding a thumb in to replace his dick. Then he looks up at his best friend and is hit by a sudden wave of affection: Bucky put off becoming their boyfriend just so Tony could have this final night of fantasy.
Because Bucky is sweet like that. He knows how much this arrangement has meant to Tony.
When their eyes meet across Tony's body, Steve can't help smiling. "I think it's time, don't you?"
The excited grin Bucky shoots him goes straight to Steve's cock, propels his hand from Tony's mouth to wrap around it and squeeze to keep himself from going off.
Bucky pulls his metal hand off the bed, where it's been keeping him anonymous when not covering his lush, panting mouth, and clamps it around the back of Tony's neck.
Steve withdraws his feet from Tony's wrists. Immediately, Tony reaches for the hand on his neck, feeling and then holding on as his eyes clench shut and his mouth drops open wide with a plaintive wail. Because even sex- and sleep-muzzy, Tony Stark remains a genius. Steve sees the moment he realizes there's only one man Steve would let fuck him who also has a metal left hand.
"Buck—" Tony's back arches, and then he spasms and comes, untouched, all over the sheets.
Bucky groans and stills for long moments. He looks up at Steve uncertainly.
"Keep going," Steve tells him, stroking Tony's hair as he shudders and slowly comes down. "Don't worry 'bout him—use him 'til you're finished. That's what he's here for."
Tony moans and shivers, bucking against the sheets without seeming to realize it. Steve smiles proudly at him.
Bucky can't seem to help being a gentleman though, and slides his hand around to palm Tony's dick.
Steve snorts. "Don't bother—he won't get hard again for a while. Doesn't mean he's not into it. Do things right and he can shoot soft." His smirk is downright predatory when he fairly croons, "Or stay hard and come so many times he cries."
Tony releases a gratifying whimper when he hears that.
It's been too long since Steve strung Tony out like that… But that's for another night. Tonight, well. Steve's voice is husky and rough when he tells Bucky, "Fuck him hard enough, long enough, 'n he'll start coming dry."
Tony reaches desperately for Steve's cock.
Steve kindly slides the tip into his mouth to give Tony something to focus on—when Tony's not so far gone his eyes are rolling back in his head, anyway. God, the way Tony's tonguing Steve's slit should be illegal. He feels a wash of heat sweep through him from the warm curl of Tony's clever tongue. "We should—" He trails off with a gasp. He can't help thrusting a little before he masters himself, remembers the plan. "We're gonna do that tonight. Get him so fucked out he's knocked out. Since you're gonna be our boyfriend now, that's a good trick to learn."
Tony's ass flexes—prompting a strangled, "Fuck, sugar, do that again," from Bucky—and the hand not gripping Bucky's metal wrist scrabbles up Steve's thigh, short nails digging in as Tony drops Steve's cock and keens into the pillow.
He doesn't tap out.
So Steve chastises him. "Unh uh," he says, and slips his cock back into Tony's mouth, then slides in deeper. "Be a good slut and keep sucking. You wanted cock and we're gonna give it to you, baby." He grins, winks at Bucky, and turns his proprietary gaze back on Tony. "Me and Bucky can do this all night."