It starts off as a joke. If Tony had known Steve would abuse the privilege to lock him out of his own damn lab, he never would’ve granted him access in the first place. And really, it’s not like two straight days of working is anywherenear Tony’s record.
Bored and sleep-deprived, he camps out in front of the TV, mindlessly flicking through the channels when one of the entertainment shows grabs his attention. On the screen is a paparazzi picture of Steve, taken on one of his runs, with the caption “Best Booty.” The hosts spend five minutes discussing Captain America’s “patriotic buns.“
Tony grins, the perfect plan for revenge forming in his mind, and goes in search of the one person who can make the execution possible.
One hour and a trip to Michael’s later, Tony and Natasha are sprawled on the floor in her room with fabric glue, glitter, and Steve’s entire collection of sweatpants and running shorts.
“That oughta teach him to lock me out of my own lab,” Tony says gleefully as he writes ‘HOT STUFF’ across the back of Steve’s favourite pair in pink glitter.
The following morning, Tony wakes up early, grinning into his coffee as he waits for Steve to return from him run. Bruce casts him suspicious looks, but Tony ignores him, feeling more cheerful than he’d normally be at such an early hour.
“Good morning,” Steve says as he walks into the kitchen, heading straight for the fridge. The shorts he’s wearing are black and incredibly well-fitting. On the back, ‘JUICY’ stretches over Steve’s asscheeks in purple glitter.
“Um. Steve?” Bruce asks, his spoonful of oatmeal halfway to his mouth. “Are you aware that your butt is… glittery?”
Tony bites on his fist to stifle his laughter, anticipating Steve’s reaction. Oh, God. He should be recording this. Steve is going to turn red as a tomato, and he’s going to be mortified upon realizing he went out in public like that—
“Mmm,” Steve says, taking a sip of orange juice before giving a little shrug. “Someone thought it’d be funny to mess with my wardrobe,” he adds, reaching to run his hand over the glitter. Over his ass. “I kinda like it, though.”
Jan walks into the kitchen then, stopping short when she notices Steve’s pants. “Well, it ain’t wrong,” she says, proceeding on her way to the coffee pot.
Half an hour later, the pictures of Steve’s glittery buttocks are all over the web. Twitter crashes.
A week later, Tony realizes what he should have a long time ago: you can’t one-up Steve Rogers.
Not only does Steve genuinely not mind the newly bedazzled state of his workout gear, but he’s taken to wearing nothing but the pants Tony and Nat decorated during their craft hour.
The thing is… Steve’s ass is distracting. It’s always been distracting—Tony is a mere mortal, after all—but even more so when Steve’s walking around with things like ‘KISS’ and ‘SEX’ scrawled over it like a neon sign. (For one of their private sparring sessions, he’d worn the pair that says 'COCK.’ Tony really hadn’t thought that one through.)
Really, at this point, Tony wouldn’t be surprised if he’s conditioned to get hard any time someone mentions glitter or sweatpants.
It all comes to a head on a Friday afternoon. Tony is in his lab with Rhodey, working on some upgrades for the War Machine armour when Steve walks in carrying two cups and a whole pot of coffee.
“Sam said you guys have been down here for a while, figured you could use some fuel,” he says with a smile.
The maroon sweatpants Steve is wearing are brand new, Tony notes with triumph. He probably had enough and switched out his entire wardrobe. Feeling victorious, Tony grins, congratulating himself on his genius. That is, until Steve turns around to put the coffee down.
‘STARK’ is written across his ass in gold glitter.
Tony’s jaw drops to the floor. Steve hands him his cup, his fingers covered with traces of glitter.
“Uh,” Tony says dumbly, staring at the ring of sweat on the collar of Steve’s shirt. “Are you… Did you just come back from a run?”
“Yep,” Steve confirms, popping the ‘p.’ There’s a mischievous glint in his eye.
Steve went out in public. With Tony’s name on his ass. Holy. Shit. The internet is going to explode. Fox News is going to have an aneurysm.
Steve gives him a meaningful look, lowering his voice to an almost lecherous register. “I’m going to take a shower.”
With that, he walks out of the lab, leaving Tony to stare at his beautiful ass as he departs.
“Oh my God,” says Rhodey.
“What the fuck,” says Tony.
“So much brain bleach,” Rhodey mutters, burying his face in his hands. “I’m going to need so much brain bleach. Have you invented that yet?”
“Did… Did Captain America just proposition me?” Tony asks, because he’s pretty sure the last of his brain receptors has been fried.
“Dude,” Rhodey says, giving him a pitying look. Tony is a fucking genius, thank you very much, but Rhodey is looking at him like he’s a poor, lost puppy. “He literally spelt it out for you. On his ass.”
“Well. Looks like your upgrades are going to have to wait, honey bear,” Tony says, getting up from his seat. He tries not to run across the lab, but it’s a close call. “I’m gonna go get intimately acquainted with a certain Stark-spangled ass.”