Quick Author's Note: I originally posted this on my AO3 account, there's a link to it on my profile page. I decided to post it on here because reasons. (The link to my tumblr is also there btw Follow me pls)

Tony Stark is, by most people's standards, an average-sized man. He's toned, but still lean, and he's a little shorter than some men but he's still got some good height on him. Steve's aware of this, of course, but not obsessively so.

Until, that is, Tony's writhing against him, pinned to the wall, feet dangling off the ground as Steve hikes him up to his own height, and kisses him as hard as he can, tongue diving into Tony's mouth and hands wrapped around Tony's wrists, pinning them above his head. Tony moans, tilting his head back and Steve drops down to press his lips softly against Tony's neck. Compared to Steve's, even Tony's neck is small.

Tony's legs swing up and wrap around Steve's waist, pulling him closer and pushing their hips together. Steve groans against Tony's skin and Tony gasps softly. Tony's never one to ever submit, or admit defeat. Except, of course, when it comes to Steve.

Steve doesn't know why Tony lets him do it, completely dominate him. He doesn't quite understand why Tony lets him do some of the things he does. He pins Tony down, pressing his shoulders into the bed and hikes his ass up for Steve to view and Steve- god, it fucking destroys Steve's inhibitions and he lets go, dominating Tony to the point of where he knows that if Tony wanted him to stop, he probably couldn't. Or when Tony lets Steve choke him, whether it's with his hands or his dick, and Steve loves the way Tony's throat moves and squeezes when he's on his knees, taking Steve right to the base. And again, it's one of those moments where Steve isn't sure he could ever stop, and the feeling of the man that is so much smaller than him submitting to him is just... mind-blowing.

Bringing his attention back to the pinned man on the wall, Steve grinds his hips onto Tony's, feeling his breath hitch and his stomach tighten as he moans softly and grinds back.

Steve's hips snap forward and one hand moves down Tony's body, the other one still barely large enough to keep Tony's hand captive above his head. The hand travels down further and further, rubbing his stomach before moving to his back, lower and lower and then gripping the jean-covered flesh there tightly, kneading and pushing and cupping and the sounds Tony makes as he thrusts forward into Steve's hips and then rests backwards into the palm of Steve's hand are dizzying Steve's head.

He pulls away, setting Tony softly back on the floor. Tony stares at him for a moment before backing against the wall again, and then slowly, he sinks to his knees, putting his hands behind his back and looking up at Steve. Steve's breath is taken away by that sight, Tony on his knees, beautiful brown eyes wide with need and lust and his mouth hung open slightly. And the hands behind his back, like he's tied up is... Jesus, Steve might have to go to the hospital soon.

Steve saunters forward dipping his hand into his pants and into his boxers, gripping his cock tight and pulling it out, and Tony whimpers at that. That sound makes Steve go crazy, having to grip his dick at the base and stroke to the tip to relieve some pressure.

Steve stops, his cock just a couple inches away from Tony's face and Tony groans, looking up at Steve. Their eyes meet and Tony whispers, "Please."

Steve groans and shifts forward, grabbing the back of Tony's head and pressing his cock against Tony's lips. Tony parts them, and Steve thrusts forward, bringing Tony's head forward to meet his groin and slams into the back of Tony's throat. Tony moans deep in his throat and the vibrations fill Steve, making him pull out and then buck back in again.

Tony's just sitting there, whining and moaning as Steve thrusts in and out, cock sliding against Tony's tongue and then down his throat, filling him and making him cough with a need for air. Steve knows he likes it, though, and the sounds Tony's making as he's on his knees only confirm that.

Steve pulls back and then snaps his hips forward again, shoving himself deeper into Tony's throat, and the force of his thrust makes Tony's head hit the back of the wall which makes Tony whimper.

Steve pulls out then, leaving the shining, spit-covered head of his dick leaking against Tony's bottom lip and Tony looks up at him, flicking his tongue out and licking Steve's tip. Steve gasps, reaching down and grabbing Tony's chin in his palm and forcing his head back against the wall. Tony barely has time to make any noise before Steve snaps forward again, pushing his cock as far down Tony's throat as it will go. Tony groans, tightening his lips' hold on Steve's cock and swallows, making Steve shoot pre-cum down his throat.

Steve then pulls out and thrusts back in, this time at a more rapid pace, his thighs slapping against Tony's face and Tony's eyes close and he coughs lightly, drool coming from one of the corners of his mouth as Steve keeps on throat-fucking him, his head banging against the wall.

With one thrust more, Steve brings Tony's head forward, shoving his face into his groin as he pushes his cock as deep into Tony's throat as it will go. He relishes in the tight, wet heat, feeling Tony swallow around him and his throat muscles massage Steve's dick and Steve lets out a long groan before pulling out, seconds away from cumming.

Tony's panting, resting his head against the wall and closing his head, chest heaving up and down. His hands sneak out from behind his back, trailing across his hips before one dips into his jeans, jerking his cock fast and hard.

"Mm, fuck, that feels so good when you do that, Steve." Tony's voice is throaty and raspy, and it ignites the fire inside Steve that he was able to do that to him.

Grabbing Tony by his shoulders he lifts him up, kissing him roughly, tasting himself of Tony's tongue and he groans at that before pulling away and ripping all of his clothes off- and Tony's, too.

Finally, while standing there, staring at each other, and breathing heavily, Steve takes in just how much smaller Tony is than him. He's at least four inches taller, much more built and, although Tony isn't too small, Steve's quite a bit bigger than he is, by three or so inches.

Steve grabs Tony's arm and pulls him down onto the bed, letting Tony straddle his waist. Again, Steve must take in Tony's stature, especially now that he's on top of him.

Steve reaches over to the drawer and pulls out a tube of lube, handing it to Tony. Tony pops it open, pouring some into his hand before reaching around and stroking Steve's cock, coating it. Steve moans as Tony does that, squeezing sometimes and twisting at the base.

"S-Stop, you're gonna make me cum." Steve gasps.

Tony throws the tube off the bed and then raises himself up, before he begins to slowly sink down on Steve's cock.

The head presses past the tight ring of muscle and Tony gasps, planting his hands flat on Steve's stomach for leverage. He bites his lip, occasionally crying out as he sinks down, filling himself with Steve's cock and Steve has to grip the sheets himself to keep from bucking up into Tony because Tony is ready yet, but god, he's tight, and hot, and feels so perfect around Steve.

Once he's totally seated, Tony looks up at Steve, panting softly, and then lifts his wrists up to Steve's face. Steve stares at him with wide eyes, and then asks, "Really?"

Tony nods, and it kills Steve a little when he sees a couple tear-tracks on his face because he knows it has to hurt, but Tony loves it, and he knows it, but he still says, "Just... just promise me you'll tell me, if you want me to stop."

Tony nods and then Steve grabs his wrists, twisting them around his back and holding him there, and then Tony slides up, gasping at the feeling and then sits down, moaning.

Steve throws his head back, groaning at Tony's heat moves up and down on his cock, filling Tony and then pulling out to where the head is barely still inside him, then Tony sits back down and Steve's grip on his wrists tightens.

Tony moans as he rides up again, and then when he goes to sit back down Steve's hips buck up, as if they have minds of their own, and slam into Tony, making him cry out.

But he still doesn't say 'stop'.

Because he loves it when Steve begins to take control. He loves how much bigger Steve is, and how much stronger and how small Tony is in comparison.

Tony begins to quicken his pace, after feeling Steve strike the spot deep inside him that turns him into mush, rising up and sitting down at a quickened pace and Steve's hands have to leave his wrists to go to his hips, gripping them tight as he thrusts up to meet Tony.

And then, then Steve takes over. Tony sits down and then stares at Steve, and Steve grips his hips and lifts him up, pulling him up and down on his cock, Tony's ass slapping against Steve's thighs and filling the quiet air with harsh sounds. Steve thrusts every time he pulls Tony down and Tony's head hangs back as he lets Steve control him, crying out, whimpering, moaning and gasping every time Steve slides into him.

And Tony's weight is so easily movable and Steve fucking loves it. He loves how this is when he gets off on how small Tony is, how Tony lets him use him as a toy, fucking him while he sits there and lets him. And Steve worries then that he's hurting Tony, and at that point he knows he probably couldn't stop if Tony wanted him to, because even though the guilt of breaking Tony would haunt him forever, using Tony Stark as his own fuck toy is too much of a kink to let go of.

Steve leans up and grabs Tony's wrists again, forcing them behind his back as he pounds into Tony, Tony bucking up and releasing pathetic and powerless sounds as Steve fills him and Steve's so big, he's in shock at how he can even fit inside of Tony.

Fucking Tony, using him is far better than any masturbation Steve had ever done to himself. They're moving together, Tony's hands behind his back, restricted by Steve, who's using his hole to get himself off, their bodies slapping together as Steve moans and Tony cries out and whines and gasps, and he mewls and makes small sounds as Steve fucks into him, pace quickening.

Steve's about to cum, he knows he is, but before he does, he opens his eyes, getting a glance at the sight and he loves it, it's encrypted into his mind now. Tony's head hanging, boneless and weakened as Steve fucks him, letting himself be taken over.

The thought alone kills Steve and he cums, shooting into Tony so hard he can't make a noise, so he lets out a breathless scream as his vision whitens, pleasure consuming him from head to toe.

Once it subsides, he lays his head back, gasping for breath and Tony pulls of him, sitting on his stomach, staring down at him with a half-lidded smile.

He's still hard, aching for release, and Steve knows just what will get him that release. Reaching down, he cups Tony's ass and pushes him up, and then his fingers press against his destroyed hole. Tony whines and thrusts his hips up, and Steve flips them over, laying beside Tony as Tony holds onto him and Steve fingers him, first just one finger, then two, and now three, rotating and spreading his sensitive hole even more. Tony's writhing, crying out and finally, he cums, without ever touching himself, head throwing back into the pillows and moaning a deep and beautifully destroyed moan that is pure music to Steve's ears, he could listen all day.

The sight alone gets Steve hard again, which Tony notices immediately, and he looks from Steve's cock to his eyes, and then gives him the OK, and Steve rolls on top of him, pinning him down, going in for another round, and much more after that, because he can't get enough, especially tonight.