It starts, as many things do, because Tony has no concept labeled ‘too much information.’
They’re eating breakfast at the Tower, and Tony is telling tales out of school to Thor, fresh from Asgard and looking awfully happy about the fact that Doctor Foster is based in New York these days. Well, it’s hard to miss: Bucky’s pretty sure that anyone within three floors of Thor’s room heard their reunion last night, and Steve’s ears have turned pink every time he’s looked at either of them this morning.
Bucky kind of likes it when Steve blushes.
So breakfast ends, and the three of them head downstairs to the practice rooms, and Bucky says, casually, “You know, I’m pretty sure someone’s going to have to explain half that story to Thor at some point, and it ain’t gonna be me.”
Steve says, “Yeah about that-- I picked up some of it from context, although I’m not sure what a TARDIS is or why you’d put one on the roof of the MIT library. But I’m a little unclear about what he needed the handcuffs for and I haven’t got a clue what pegging is.”
Bucky looks at Natasha, a little helplessly. “Nat, you wanna jump in here?”
“Not really,” she says crisply, but relents. “Oh, fine. Steve, the handcuffs were for sex. As was the pegging.”
Steve’s ears turn pink again-- the man’s been fucking them both for six months, you’d think he’d have his blush reflex under control, but that’s Steve all over. “So what, exactly, is--?”
Bucky is tempted, so tempted, to let JARVIS handle this one, but he’s pretty sure it would get back to Tony and they’d never hear the end of it. “It’s sex with a strap-on, Steve. Where the woman fucks the man.”
And now Steve’s ears are flaming scarlet, his face pinking up too. “Um, okay. That’s. Um.”
Bucky slings a careless grin at Natasha, whose expression is, as always, carefully controlled. The corners of her mouth turn up, briefly. “The next words out of his mouth are gonna be ‘You can do that?’ Just watch.”
“Well, they would have been,” Steve admits, “but you beat me to it.”
There’s a companionable silence, Steve’s expression equal parts wondering, turned on, and guilty. Nat’s eyes are amused. Finally, Bucky says “We could try it, if you wanted.”
He didn’t think it was possible for Steve to get any redder, but shows what he knows. “I, uh-- I mean, that is--”
“Relax,” Bucky says. “It was my idea. You in, Nat?”
She raises a considering eyebrow. “Might need to do some shopping first.”
“Oh, god,” Bucky laughs, and gestures at Steve. “We’re not getting him in a sex shop.”
“I’m pretty sure this is why they invented shopping on the Internet,” Steve says, a little primly. “But, um. If you wanted to.”
A week or so later, a plain brown box arrives at the apartment Natasha keeps for plausible deniability, because sending it right to the Tower would be asking for trouble. Its contents come to Steve’s room in said Tower, because he’s got the biggest bed.
“So, um.” Steve looks uncertain, and he’s blushing again. Bucky smirks sideways at Natasha, who laughs one of her rare, unguarded laughs.
“Go on,” she says, fond and amused. “I like to see you two.”
“C’mere,” Bucky says. He wraps a hand around the back of Steve’s neck and pulls him in for a slow, lingering kiss. Steve’s not quite so pink by the time they break apart.
They undress each other carefully, and maybe Bucky’s not the only one who’s tense with anticipation. Once the clothes are all off, Natasha pushes Steve back toward the bed, until he’s sitting up against the headboard, legs splayed out in front of him. Natasha pauses a moment, kissing him while Bucky watches appreciatively. God, but they’re gorgeous, and all his. He’s a lucky son of a bitch, sometimes.
Steve kisses Natasha until the tautness goes out of her shoulders, until her movements are loose and gentle instead of sharp and controlled. Not for the first time, Bucky thinks about what a fucking disaster he and Natasha would be, without Steve to remind them both that they’ve got hearts under the scar tissue.
Natasha stands back up, a small satisfied smile playing around the corners of her mouth, and now it’s Bucky’s turn to be led over to Steve’s big bed and settled into place.
She arranges him between Steve’s legs, head tipped back against Steve’s warm broad chest, the two of them just breathing together while Natasha puts on the contents of her plain brown box. Steve’s hand skims across Bucky’s stomach, and his breath hitches a little when Steve strokes his hardening cock and bends to kiss his throat. His grip tightens on the sheets.
He could always feel pressure with the prosthetic arm, and now a little bit of sensation in the new one Tony made for him, but it’s blunted, remote, and has the odd side effect of making his good arm feel more sensitive than it ever did in the old days. So Steve’s free hand stroking along the skin on the inside of his wrist is almost as unbearable as Steve’s other hand jerking him off.
“Slow-- nn. Slow down a little,” he murmurs, and wriggles back against Steve’s own cock, pressed hard against the small of his back. Steve’s hips hitch in a gratifying way. “I don’t wanna miss all the fun.”
And that’s when Natasha turns around, and if he was hard before he’s aching with it now. The strap-on’s not huge-- Steve is bigger, certainly-- but proportional to Natasha’s slim frame, and the glint in her eyes promises all sorts of good things.
She crawls into his lap to kiss him, slow and dirty and teasing, her hands and Steve’s tangled on his hips and holding him still. Bucky’s pretty sure there is no better place in the world than here, between the two people he loves most; certainly there’s never been anywhere he feels safer. He moans into Natasha’s mouth, and digs his heels into the mattress as she sucks on his tongue.
Kissing’s all well and good, but Bucky was under the impression that they were gonna do a little more than kiss tonight. “C’mon,” he mumbles into Natasha’s mouth, needy, almost a whine, “let’s get this show on the road.”
She laughs a little, low in her throat, and Steve makes a fond, amused noise that Bucky can feel in his chest. “I can do that,” Nat says, and reaches for the lube. A minute later, two slick fingers are pressing just exactly where Bucky wants them to be. “Okay?” she says, and at his nod Natasha slides her fingers in, and in, and oh, it’s good, and Bucky knows it’s just the pre-show. The main attraction’s going to be even better.
“Steve, you too,” Bucky manages to say between moans, and Bucky can feel Steve’s skin get hotter for a moment. Then Steve’s hand is fumbling next to Natasha’s, and yeah, yes, good, that’s just what he was hoping for. They move together like that, the three of them, until Bucky’s biting back the noises he wants to be making, trying to keep his hips under control.
“You ready?” Steve murmurs in his ear.
“God, yes,” Bucky says, with feeling.
They pull their fingers out, and Bucky has a moment to collect himself while Natasha slicks up the strap-on. Her eyes are dark, pupils blown as she sits back on her heels, and he takes a moment to appreciate the lines of her body. He hadn’t had much input in the contents of the brown box, just trusted Natasha to pick something that would be good for both of them; he’s pretty sure she’s succeeded, from the pleased purr in the back of her throat as she leans over him.
She eases the head of it in, slow and careful, and then rolls her hips just hard enough to make a ragged noise in Bucky’s throat. She works it in like that, one thrust at a time, while her sharp nails rake through his hair and Steve’s hands steady his shaking thighs. She leans forward enough to catch his mouth with her own, and the change of angle makes him arch and gasp against her lips.
He’s saying nonsense things, he knows, in Russian and in English, while he falls apart under her thrusts and Steve’s careful hands. Fuck, but he is so, so lucky--
Natasha speeds up a little, her breath coming almost as fast as his, and there’s a fierce glitter in her eyes. “C’mon, James,” she says, low and totally, totally deadly, armed and fucking dangerous, killing him a little with every hitch of her hips. “C’mon and-- ah--”
Hearing that noise come out of Natasha, that little slip in her control, would maybe have been enough on its own, but Steve chooses that moment to grip his cock again, and it’s too much. He arches again, harder this time, head tipped back against Steve’s shoulder so his throat’s exposed. Steve takes the opportunity to bite the straining tendon there, to gentle it with a softer kiss as Bucky comes, the feeling white-hot behind his eyelids.
He sags, suspended between them as Natasha slows down and comes to rest against him, as she pulls out and strokes at his trembling thigh. They pause like that for a moment, all three of them, letting their breathing slow down enough to figure out what comes next.
“You really need to fuck me now,” Natasha informs Steve, and Bucky can feel the chuckle rumble up through Steve’s chest. He carefully slides Bucky sideways, and lets him settle, boneless and spent, on the pillows beside him. Bucky curls onto his side and watches through half-lidded eyes as Natasha unbuckles the strap-on with hands that are just a shade unsteady, just enough for someone like him to notice. And then Steve is rolling them over so she can wrap her legs around his waist, and they are moving together so, so beautifully.
If Bucky could at the moment, he’d get hard again. But he’s a little bit too wrung out.
After, they lie in their customary tangle, Steve absently petting Bucky’s hair, Natasha petting Steve’s. “We should do that again,” he says, after a while.
“Yeah?” Bucky asks, and props himself up on one elbow to meet Natasha’s eyes. She quirks an eyebrow at him, and he knows they’re wondering the same thing. “You wanna try it next time?”
Steve considers this, and when he says “Yeah. Okay,” he doesn’t blush at all.