"Well, that was quick," Natasha comments without so much as a glance at the entrance. Tony traipses in, and slams the door shut. It's all manual labour from here on out obviously. None of the motion sensors are working. He limps over to her, who's commandeered the plushest stool she can find that hasn't yet been obliterated in the explosion. "You're still alive, at least."

"Yeah, about that." What she doesn't know won't hurt her. "Totally kicked Rogers' ass. Wish you were there." She tosses him a piece of cloth that's meant for polishing engines. Hey, it's the thought that counts, right? "Anyway, did you grab the shield? I've a suspicion he won't be looking for it anytime soon," the edge of his lips twitches a bit.

"About that…"

"Shield, Nat." He checks the table closest to him. "Where is it?"

This isn't fair. Standing in for Natasha isn't his idea in the first place, and after getting his ass handed to him upstairs, the least she can do is to present him the shield, wrapped up in a bow with confetti bursting from the ceiling. "This isn't our deal, Nat. You're the superspy here, how difficult can snooping around Steve's room be? Hell, he seems the type to leave his door unlocked." And that's when he notices the peek of bluish glow from Natasha's collar. He swallows thickly, and is rudely reminded of the loss of his arc reactor. Being female is odd enough an experience to take his mind off the absence of a dead weight in his sternum.

He sighs, and drags another stool to sit on across Natasha. "It's that thing, right?" He taps on his own chest, finding supple flesh instead of bones. "Sorry about that."

"Does it feel this way all the time? Or is this just a bad day?"

"Well." No need to be so dramatic. "I got used to it. Anyway, I feel like I need to tell you – be careful with that, will you? You don't want it detached from the housing at all. It needs some servicing from time to time, but I think I can reverse 'us' before then. OK?"

"… OK."

"OK. And uh, if it's fine with you, I wish to avoid Steve at all costs from this point onward."

And Natasha raises a dark brow. "Why?"

"Or, let me rephrase that. I may be a superbly gifted multitasker, but I think I want to focus on fixing this." He smacks the control machine with the flat side of his fist. "We haven't spent more than two hours in each other's bodies, and I'm tired of it already. Which is weird, because I've spent a good deal of my youth fantasising about being a woman –"

"Thank you!" She slaps her thighs loudly enough Tony himself winces. "OK, come here." She gets up and motions at her recently vacated seat. "Can't have you working on the machine looking like that."

"Looking like what?"

"Like roadkill. Sit."

As he sinks into the cushion, Natasha has somehow conjured a first aid kit from thin air and taken out alcohol swabs. The pungent sterility is so permeating Tony turns his head away the moment Natasha attacks his temple with it. She works diligently as she is silent, and Tony steals a couple of glances at her chest. His, technically, but he's never seen it from a third person's point of view, duh. There's something enthralling about the glow, and he's hypnotised. It's beautiful, aesthetically, scientifically… it's his burden to bear. Not Natasha's.

"You OK?" She presses the wad of cotton into the bridge of his nose where Steve's magnificent knuckles made contact.

He flinches, "The reactor still troubling you?"

"It does make me wonder how deep the housing actually goes."

"… Deep enough to do its work. Lucky you, I've developed a trick to make it feel better. Wanna see?" He takes her by the hand and manoeuvres her into the opposite stool. "Pardon me." He holds out his hands, palms facing up and slowly, he reaches over to Natasha's collar. He takes out the first three buttons, and the arc reactor comes into full view. "Ready?" A touch of playfulness lights up his eyes. "Might be ticklish." He presses three petite fingers into a tender region about half an inch below the arc reactor. "Always does the trick."

"… Your fingernails are long, Stark."

"They're really yours."

"… You sure this is you? Or did the machine swap your personality with Dum-E or something? I mean, Dum-E's nice."

Tony huffs, an easy smile lingering on his glossy lips. But he says nothing.

"I mean, you have a reputation."

"Yeah? The party days are over, Nat."

"What changes?"

"… You." The smile on Tony grows. "Pepper. Steve. The Avengers." Then he rolls his eyes and quickly waves a hand absent-mindedly. "You guys won't last a day without my charity, is what I mean to say."

And then, gravel crunches at the lab's entrance. They both start, heads immediately snapping to the intrusion presented in the form of – to their horror – Steve Rogers. His eyes are as wide as dinner plates as he watches Natasha, still dressed in her armoured bikini, sticking her hand against Tony's chest, whose dress shirt has parted halfway.

"I… just wanted to see if you're all right, Nat," Steve explains hesitantly. "I'll leave you guys to it."

Then, he's gone.