“Oh my god Tony, just shut up already,” Steve says finally. He didn’t understand any of the technobabble the other man was spouting, and he just wanted him to stop talking.
Tony gives Steve a wounded expression. “But…” he begins, but Steve cuts him off before he can launch into technobabble again.
“Tony either shut up or I’ll make you shut up,” he says, a commanding tone to his voice. Steve can tell the exact second Tony catches on to the meaning of Steve’s words as his entire demeanor changes. If he were anyone else, Steve would be concerned by how quickly Tony switches from annoying as hell to submissive. But this is Tony, and Steve suspects that he ramps up the annoying when he wants to be pushed into subspace. He thinks normal person would simply just ask instead of provoking their dominant, but being normal and being a Stark don’t exactly go together.
“I’ll think you’ll need to make me,” Tony says, his voice still defiant even when the rest of him is showing every sign of submission.
“Knees,” Steve says, as he crosses the lab to Tony’s workstation, his dick getting half-hard at how quickly the other man obeys his command. He places two fingers under Tony’s chin to tilt his head up to look at him. “You want me to find a better use for that mouth, don’t you Tony?” he asks.
“Yes, sir,” Tony says softly.
“Good,” Steve replies, opening his jeans and pushing them and his underwear down far enough to reveal his cock. “No hands, you’ll know when I want you to stop.”
Steve groans when Tony licks a stripe up his cock and then buries his fingers into the other’s man’s hair when he takes his length into his mouth. He lets Tony control the pace for several minutes before tightening his grip in Tony’s hair and thrusting his hips forward. He knows he’s probably more careful than he needs to be while fucking Tony’s mouth, but he’s had bad experiences while being on the receiving end and he wants to make sure the same never happens to Tony. He’s also not trying to get off right now, as he has other plans for Tony. The serum did reduce his refractory period, though despite the speculation that Steve pretends he doesn’t know about, it’s not non-existent. When he feels himself getting close, he tugs on Tony’s hair and stills his hips in a signal to stop. Tony whimpers as Steve’s cock slips from his mouth, but other than that he stays quiet, which Steve selfishly finds one the the favorite parts of having the other man submit to him.
He tugs Tony to his feet and kisses him before turning him around and bending him over the workstation. They’ve done this enough times that Steve knows where the lube and condoms are stashed without having to ask, and he watches Tony as he gets them. He sets them within Tony’s line of sight as he tugs his pants and underwear down to his knees. He picks up the lube, leaving the condoms where they are for now. “No coming until after I do, remember?” he asks, as he slicks a finger with lube.
“Yes sir,” Tony breathes out, gasping as Steve’s finger brushes across his entrance.
“What’s the other rule?” Steve asks, continuing to tease Tony’s hole.
“If I want more, I have to beg for it,” Tony practically whimpers. “Please can I have your finger inside me?”
Steve can’t help but smirk. Tony normally doesn’t start asking this soon, but he’s also still in the polite request phase and not the begging phase, so Steve isnt’ going to give him what he wants just yet. “It doesn’t sound like you really want it,” he replies.
“The fuck it doesn’t,” Tony mutters, which Steve pretends not to hear as they don’t have enough time for Steve to threaten to stop every time Tony tries to push him. Fortunately, Tony gets the message as he next words are far more desperate sounding. “Please… need your finger inside me.”
Steve rewards Tony by pressing his finger inside, stilling briefly to give Tony a chance to adjust before fucking Tony with his finger. “You like this don’t you Tony,” he asks. “My finger fucking you like my cock is going to.”
“Yes sir,” Tony moans out. “Please… I need more…”
Steve pushes aside his desire to hear Tony beg more in the interest of knowing they’re in a public space and preferring to finish before they walked in on. He presses a second finger inside Tony and immediately seeks out his prostate.
“Fuck,” Tony cries out in surprise, as Steve usually avoids that spot as long as possible.
“Can’t take my time right now,” Steve murmurs. “Unless you want someone to see you like this.” While they both get off on the fact that they could get caught, neither of them wants that to actually happen.
Tony shakes his head the best he can from his position. “Please sir, I’m ready for your cock sir.”
Steve’s eyes widen as he usually uses three fingers to prep Tony. “Are you sure?”
“Yes sir,” Tony replies. “Want to feel you after.”
Steve pulls his fingers out of Tony, choosing to trust his judgment. “Use your safe word if it’s too much,” he murmurs, wiping his fingers off on his jeans before picking up the condoms. He rolls one on Tony as they can’t afford to make a mess in the lab, before putting the other on himself. He slicks up his cock, before pressing into Tony at a slow steady pace. He pauses once he’s fully inside him, but when Tony simply says “more” instead of his safe word, he starts to fuck him hard and fast, brushing across Tony’s prostate with every thrust. He feels himself on the edge far too soon and reaches a hand around Tony to stroke his cock as he comes. “Come for me Tony,” he murmurs, and the other man is so on edge that Steve’s words are all that it takes for that to happen. He pulls Tony up into a kiss as he disposes of the condoms and they barely enough time to get their clothes righted before Bruce walks into the lab looking for Tony, oblivious to what he would have interrupted had he arrived any sooner.