Bruce doesn't waste time following Tony around. Once it's obvious that (they both should be committed) that Tony is committed to this direction, Bruce takes the path of least resistance and jogs back upstairs to find his bug out bag, the one he'd left behind when he left the tower behind. For him, having that backpack is true luxury.

In the meantime he tells FRIDAY to put a rush on his amended food order.

He's quite certain that he's lost his mind.

Back downstairs, he fumbles at the tuna can and gapes at Tony. "That's your stipulation? Fine, but you can't sleep with her either. That would be taking a scarily narcissistic turn."