Well, the captain has a point there. If Bruce was a timeshare, he'd probably be getting something out of it. But saying anything like that gets shelved and his eyes go wide open.

"Come downstairs?" he echoes in confusion. "Like. Down here downstairs?" There's a wince at how stupid that sounds as he hauls himself back into a sitting position. "Uh. Sure thing, I mean. If you wanted to. It's not l- You can go wherever you want, you don't really need my permission to."

...If Captain America is coming to his room, it would probably be a good idea to tidy up some.