A/N: Heeeey another update! And it hasn't even been like a month yet. And in case anyone who reads this also reads Broken, I should have an update for that fic up soon. Enjoy!

Bucky knows that Tony doesn't like him down in the lab but Steve is out grocery shopping for the second time this week and Bucky's tired of watching TV alone upstairs. He figures he should being a peace offering of some sort in case Tony is in a mood, so he brews a cup of strong coffee with Tony's version of a Keurig and heads downstairs.

Bucky doesn't even try to sneak in or be quiet when he reaches the lab. He enters the code and slips through the door with a steaming coffee cup in his hand and a smile on his face. It's not even a smile, just the slight upturn of his lips that never seems to go away. He finds Tony sitting in his spinning chair and slides the mug of coffee onto the desk, pressing a kiss to Tony's hair.

"Mm, hey," Tony murmurs distractedly. He glances at the coffee mug and gives Bucky a grunt of approval. He grabs the mug and takes a sip, spinning around to look at Bucky.

"What're you doing?" Bucky asks curiously, squinting at the screens that never seem to make sense.

"Stuff," comes Tony's reply and Bucky smirks because they've had the discussion about the screens before and if Tony explains it Bucky won't understand anyway. "You need something?"

"No. Just bored, thought I'd come see what you're up to."

Abruptly and without much thought Tony reaches out and takes Bucky by the wrist, pulling him forward. He catches Bucky off guard and the younger man stumbles forward, sliding Tony's chair on its wheels. Tony utters an 'oh shit' before the chair slips out from under him and he and Bucky tumble to the ground. The two of them land in a pile of limbs and the wheels of the chair jab Bucky in the leg, surely leaving a bruise

At first Bucky is pissed because Tony caught him off guard. But then Tony looks at him and he's doing that thing, making that face, the one that Steve hates, the one where Tony is trying not to laugh. His cheeks puff for a few seconds and then Tony's chuckling, kicking the chair away from their bodies.

"You asshole!" Bucky shouts and they both know that he doesn't mean it. He leans forward and lightly slaps Tony across the face, biting his lip. He isn't sure how Tony's going to react and maybe he should've asked before doing it but that would defeat the purpose and Tony is a better sport with these kinds of things than Steve is.

Tony reaches out and returns the light slap, chuckling when it wipes the smirk off Bucky's face. It's Tony's turn to smile deviously when he struggles to grab Bucky's hands, pinning them above his head and straddling his hips.

"God, we're such fucking kids," Bucky grins. He pulls at his wrists and, surprisingly, Tony's grip is rather firm. Well, firmer than Bucky expected.

Tony doesn't say much, just hums and leans down to press a tender kiss to Bucky's pouty lips. He brings a hand down from Bucky's wrists to cup his cheek and Bucky sighs deep through his nose, sliding his wrists from Tony's loosened grip. He sits up as best he can, wrapping an arm around Tony's neck and breaking the kiss. They pause just for a second in this tender moment and Tony isn't sure what to think. He cares about Bucky; he already knows that. But what Tony is becoming startlingly aware of is the fact that his feelings may be turning into something that could be defined as love.

Tony brushes his lips across Bucky's forehead before he stands up. He turns his chair to the upright position and helps Bucky to his feet. When Bucky looks into Tony's gaze his expression has changed rapidly from what it was moments ago. His brown eyes are clouded with confusion and confliction and Bucky doesn't even ask. He rubs the back of his head where it hit the hard floor of the lab and goes back upstairs.

Bucky doesn't come into the kitchen when Steve gets home with groceries. It's a thing with him and Tony, to annoy Steve and dig through every bag, sample everything and proceed to let Steve put them away by himself. But when Bucky is lying on the couch watching TV he doesn't hear Steve griping at Tony not to scatter the groceries. He does hear Steve and Tony talking in hushed tones. And then the talking dies down and Steve is doing that thing, the almost-giggle laugh he does when Tony bites his neck, and the two of them disappear to the bedroom.

And Bucky shouldn't feel left out. He shouldn't feel jealous because he knows their arrangement could go awry at any moment... but he does. He doesn't know what he did wrong to have them treat him this way. And Bucky isn't one for games; he hates them and as soon as Steve and Tony are done fucking Bucky decides he's going to pull Tony aside and demand to know what the problem is.

Bucky tries to drown out Steve's moans and Tony's grunts. He tries to watch TV and forget about everything but that proves impossible when he swears that he hears Steve moan something that sounds like 'daddy'. Bucky's cock is hard at the thought of Steve and Tony together and he can't stand it, he can't fucking stand it anymore so he pushes himself off the couch and pads down the hallway in his sock-clad feet. The bedroom door is open a crack and he squints. Steve and Tony are in perfect view and damn that's hot.

Steve is on his back, Tony between his legs, and they're both covered in a light sheen of sweat. They're moving like they're dancing and Bucky can't help it. He has to touch himself. He trails a hand down to his tented sweat pants, sliding his fingers beneath the waistband and giving his cock a firm squeeze. He hears the sound of skin slapping skin and Bucky had no idea Tony could fuck that hard.

Bucky pulls back, leaning against the wall just outside the bedroom door, sighing at his own touch as his fingers dance on his hard member. The mattress squeaks and Tony dramatically orders Steve to get on his hands and knees. And there's that sound again, the sound of skin against skin, but it's a distinct slap that gives the hint of being brought on by a hand rather than a pelvis.

"Fuck, Steve," Tony grunts breathlessly, accompanying his words with another smack.

Steve doesn't say anything - or if he does, it's too low soft Bucky to hear - but he laughs and there's a light squeak of the bedframe to signal they're changing positions. Bucky rolls on his shoulder against the wall, stealing another glimpse inside the bedroom. They're both on their knees now, Tony behind Steve, an arm around his throat and a hand over Steve's mouth. He can't hear exactly what Tony's saying but judging by the expression on Steve's face it's probably one of the filthiest things he's ever heard.

Bucky feels himself getting close. The muscles in how lower abdomen tighten and he reaches up with a free hand to pinch a nipple through his thin t-shirt. He lifts the same hand and positions it in front of his mouth, biting down as his orgasm washes over him. The sounds coming from the bedroom are too great for Tony and Steve to hear the little squeaks that escape Bucky's mouth when he spills onto his hand. He stays there momentarily, only slightly breathless from climaxing, and steals one last glimpse inside the bedroom before sneaking to the bathroom down the hall.

By the time Steve and Tony finish, Bucky has turned off the TV and he's lying on the sofa, trying to drift to sleep when he hears Steve's voice.

"You awake?"

Bucky sits up with an involuntary scowl set on his face, blinking, "Um."

"I got some news today," he murmurs softly.

"News?" Bucky retorts, searching for a readable expression in Steve's eyes. But he can't find one so he sits, patiently, trying to forget about the scene in the bedroom earlier.

"Fury's sending me on a mission. I'll be gone for the week."

"A week?" Bucky retorts. His voice cracks and he's trying not to freak out. "When do you leave?"

"Tonight."

"Where-"

"Can't say. I have my bag together and I'm about to head out. Just thought you should hear it from me."

Bucky doesn't say anything, just throws his arms around Steve's neck tightly. He presses a kiss to the side of Steve's neck, ruffling his hair between his fingers. "Be safe," Bucky murmurs.

Steve pulls back and brushes their lips together once, and then twice more. "I will. Take care of Tony."

Bucky nods, "Sure, Cap."

Steve leaves through the door and Bucky is alone again. That is, until Tony calls him to the bedroom and Bucky doesn't even have time to think about what he's doing by the time he's on his feet and moving. Tony is lying in bed, freshly showered, and there's a sort of sadness to his presence.

"C'mere," Tony murmurs. Bucky complies, sliding into Steve's side of the bed and Tony does something neither of them expects. He pulls Bucky into his arms and Bucky finds it to be the most comforting thing ever. He presses his nose into Tony's neck and closes his eyes, breathing in the scent of Tony's skin as he feels Tony's fingertips tracing circles into the skin of his back.

"Does this ever scare you?" Bucky mumbles against Tony's throat.

"Hm?"

"Steve leaving. Going on missions... the very realistic thought that he may not come back."

Tony nods. "Fuck yeah it does." They're silent for a long while. It could be minutes or hours, but what Tony says next catches them both off guard. "But if there comes a time that Steve... doesn't come back, at least I have someone here to go through that with me."