Note: Set post-Avengers. AU based on one line in Captain America: Winter Soldier
He'd finally found an apartment. It was small, inconveniently located, and poorly furnished, and it reminded him of home. Tony had offered him a place in the tower, but he'd never been one to live in the lap of luxury, and the tower was a little too perfect for his tastes. Having his own place, one where he could get away from the other Avengers, was important.
So when he unlocked the door to find Romanoff making herself at home on his couch, he was more than a little annoyed. Her casual "Hey Steve", accompanied by a wave of the beer he was pretty sure he'd purchased, didn't help.
"Funny", he said, "I don't remember giving you a key. Or the address."
"You'd need more than that flimsy door lock to keep me out", she answered. "You'd better put the groceries away. I'm sure an old man like you would be upset if the milk spoiled."
Steve did as he was told, depositing the perishables in the fridge and the non-perishables in the cupboard before joining her on the couch.
"I brought you a present", Natasha said. "I was going to wait for the house-warming party, but I'm not very good at delayed gratification." She picked up a bag from beside the couch and pulled out a stack of files. "And before you say I shouldn't have, I should point out that S.H.I.E.L.D. agrees. They don't seem to have any intention of showing these to you, so I took the liberty of taking care of it myself."
He opened the first file as she drained the last of her beer and stood, setting the bottle on the floor.
"I'll tell Fury you'll be out of town for a few days", she said, walking towards the door.
"Where am I going?", Steve asked, staring at a picture of Dum Dum Dugan.
"You'll know when you get there", she said. "Tell her I say hi."