Tony doesn't get nervous like this.

His palms are covered in sweat. His hearts beating so fast he's surprised Steve hasn't come in and asked him what was wrong. He feels like everyone within a ten mile radius would probably be able to hear it.

He's the master of speeches, he doesn't bat an eye at public speaking. He can approach any stranger and proposition them for sex, remain cool the entire time, and receive a definite yes as an answer. This feeling, he shouldn't feel this way. He's supposed to make others feel this way.

He risks his life daily, he's danced with death at every ball he's ever been to.

But the one thing he can't do is tell his boyfriend, Steve Rogers, his deepest sexual desire.

What does he even say? "I think it'd be really hot if..." or "I've always had a thing for...". There's no clever way to introduce this kind of shit.

Tony can understand introducing a mundane fetish, like feet or bondage. But no, he wasn't blessed with such an easy fetish. He has to have the worst of the worst. Something no normal person would ever casually indulge.

Diapers.

And it doesn't even end there for Tony. No, he doesn't just get off on the sight of a grown adult wearing a diaper. He wants to see it used, soiled, completely filled. He wants to see Steve humiliated.

He wants so badly to diaper Steve up, with a thick noisy diaper, completely visible under a tight pair of pants. He'd blush the entire time. Tony can't help himself, his cock grows hard. He needs to tell Steve, but he can't when he's in this state. He imagines the horrified look Steve would get when he hears the diaper crinkling loudly when he moves. "Tony, everyone will be able to tell!" he would wine. But Tony wouldn't care. He wants everyone to see Steve, so strong, so muscled, wearing a diaper.

Before heading out he'd slip a couple of laxatives into a bottle, and have Steve sit on his lap as he feeds it to him. Tony gives in, he pushed his pants and briefs down past his knees, and plops down on his bed.

He takes his hard cock in his hand, and begins to jerk to the thoughts.

He'd take him to mundane shops. Steve would keep quiet about his urgent need to go. He'd merely persist they hurry up, "Tony we have people for this! Please can we go home!" he'd say as Tony took extra care in examining items in the grocery store.

He'd bring him to the baby aisle, watch him as he internally freaks out at every mother and father who glances his way, convinced they must be able to see his bulging pants, Tony plays the fantasy out in his mind as he continues to please himself. The whole time he'd be desperately trying to keep from letting go. Everything would be so visible on his face. All the distress, the complete vulnerability. "Tony please," he'd beg.

Tony would give in, drive him home slowly. And fiddle with the codes at the front door. Steve would be sweating, trying so hard to hold it. Tony would bring him inside, help him out of his pants. Then finally, as he stands with his diaper exposed, he would loose all control. Tony would watch as Steve's face drops, a look of pure distress spreading across his face. The diaper would sag between his legs. Tony would put one hand on the diaper, and press it against Steve's ass while telling him what a dirty, dirty boy he was- and at that point Tony reaches his climax, holding in a moan as his seed spills across the sheets.