After going on almost every ride at the fun fair –

OK, no, not really. The evening has been ruined, but it's nobody's fault. Steve doesn't speak much after they got off the Ferris wheel. He broods, hands deep in his pockets as Natasha prances around, looking for more rides to have a go at. It's fairly obvious that Steve much prefers to slink back to his bachelor pad and mull over things a bit, but she's more or less mandated to keep Steve out of the Tower for as long as she can. Her cell phone doesn't buzz the whole time she's been out, so that must mean Tony is still busting ass over the machine. Since Steve doesn't want to go on rides anymore, she goes alone on the spinning tea cup, the carousel, and even walks through the haunted house. That turns out to be a mistake because barely two minutes into it, security is already hauling her out.

"Sorry, Sir," Steve apologises profusely on her behalf, "I'll keep an eye out on him. He's uh, not himself this evening."

With narrowed eyes, the burly bouncer asks, "You're Rogers, aren't you? Captain America?"

"… I wish," Steve starts scratching his chin, and fake-laughs at the ridiculousness of the suggestion. "I'll be winning big on the high striker if I were."

"Right. You best leave the premise pronto. We're not pressing charges."

"Thank you, Sir."

Steve spares her a stern look, and sighs. "We're going home, Tony."

"… I'm sorry, Steve, look –"

"It's fine. You don't have to explain."

Serve the zombie right for trying to get fresh with her though. She might have underestimated Tony's physical strength so she threw her punch like she normally would, and felt the zombie's nose crumple under her knuckles. That was thoroughly unpleasant. Her phone is still resolutely still and she desperately thinks of ways to distract Steve. Her own heart is leaping in her throat, and she herself is torn between spending more time in Steve's personal space, or faceplanting repeatedly against a stack of pillows. As if that's not tormenting enough, Tony's body is reacting bizarrely to her repressed desires, and she's infinitely glad that the cloak of night is hiding the tent in her pants from clear view, because this is wildly inappropriate. Before she knows it, they're back at the Tower's foyer, and Steve bids her a solemn goodbye.

"Hey, wait, do you want to uh, want to hit the gym together?"

Steve never says no to that.

"Nah, not tonight, Tony." He smiles wanly, and gives her a half-wave. "I'll see you around. Good night."

When the elevator door closes on Steve, she wastes no time in making a mad dash to the basement lab on foot. She slams the door open that more plaster falls from the ceiling, and Tony's head pops up like a gopher from under the control panel, and she feels an urge to wham it down with a mallet. Tony spits screws from his mouth and chucks the screwdriver he's holding towards a pile of wires and asks, "Why are you here?"

"Is it fixed?"

"No! Go back upstairs! Where's Steve?"

"In his room?"

"No, no – you can't let him! He'll notice the shield is gone and he'll call for an Assemble, or he'll be cranky at breakfast tomorrow –"

"I really think I've stretched my luck with him. I need to cool off."

And Tony looks up at her shrewdly. "Huh. What happened?"

"Nice try, Stark. What happened between me and Rogers, is between me and Rogers."

"Touché. Well, I'm not going to babysit him, and I'm so close to getting this up and running, so that leaves you –"

"I can't!"

"Seriously! I'm not asking you to tuck the Hulk into bed! Offer to help him out with something. Like with his hobby – oh, how about you volunteer to model for Steve in the nude, huh? I don't mind you objectify my gorgeous body like that, just do whatever you need to do to keep him from looking for his shield."

"Nope. If you value your life, you'll want to stay away from him for the next sixteen hours."

"Christ, what did you do to him?"

"Nothing! What am I supposed to do when he… when he…" but Tony is still ogling at her expectantly, and there is no way in hell and heaven and earth that she'll tell Tony what really happened –

"Did he ask you out? Like, finally," he rolls his eyes a little. It's Natasha's turn to pick her lower jaw up from the floor. "I mean, not asking you out while you're wearing my face. Let's not go there. Let me guess. He asked me about the consequences of dating you. Why that look of surprise?"

"… How long have you known?"

"For a while?" Tony collects his screwdriver and twirls it between his nimble fingers. "OK, here's the thing. I don't want you to take this in any way, shape or form badly, but I already had this conversation. With Steve. In my head. It's a problem, you're right. I knew you were going to say that to me and I knew what I would say in response. Take it from the expert. I know." He goes back to screwing in a metal plate onto the back of the control panel. "I see conversations coming down the street. It's just how my mind works. It's really hard for human interactions to surprise me. In fact, I was banking on it. I was hoping he would go soft on me because I look like you, yeah?"

She scoffs openly at the idea of Steve Rogers pulling his punches because his opponent has boobs. "Bet it worked well."

"He was really into the smooch though –"

"The what?"

"… Uh, the what?"

Remember what she told Tony the first time he ever hinted at doing anything weird while occupying her body? She is more than happy to go through with her threat, so she grabs another screwdriver that Tony has left lying on the workbench and she points the sharp end towards her crotch – Tony's screaming and begging for mercy –

The door swings open again.

"Have any of you seen my shield?"

More plaster snows on three of them. Steve blinks at the scene before him, and flinches at the sight of Tony trying to stab his nuts with a screwdriver. Steve's own knees might have trembled a bit. "What the hell is going on?" Then only he carefully takes stock of his surrounding, noticing for the first time how wrecked it looks. "What happened here? Looks like the end of the world!" He takes two steps forward, and his blue eyes blow wide open at the sight of his shield, lying on the floor with multiple crocodile clips attached to its edge. "Huh."

"Steve, hey!" Natasha swings her arm over his broad shoulders. "Uh, it's really kind of messy and dangerous to be walking around here, so –"

"Yeah, I'll be on my way after I get my shield back –"

"Uh, nope, can't let you do that, Cap," she quickly puts herself between Steve and Tony, one arm stretched out to warn Steve to back the hell off. "Hey, do you feel like drawing? I don't mind modelling in the nude for you –"

"I just want my shield back –"

"Just let me borrow this for five minutes, huh? Five freaking minutes, and I'll personally send it back to your room – hey!" Steve easily manoeuvres himself around her frame and strides towards the control panel, obviously wearing a mood as foul as his scowl, when he suddenly stops dead in his track.

"Nat?"

"Sorry, Steve," the static from the repulsor roars in their vicinity. Steve's face reflects the bluish glow emanating from the Iron Man's gauntlet already poised on him. "Drastic circumstances call for drastic measures. Five minutes, please."