Steve might say it's fine, but it's obviously not, he has to be nervous as hell to have even mentioned it. But of course he's going to do it, because the idiot has never backed down from a fight in his life, metaphorical or literal. Bucky's life would have been a hell of a lot easier if he had run away sometimes, he'd have had to patch up his dumb best friend less often for one.

"Do you wanna borrow Penny for the day?"

It would be good for the dog to get out of the house, and it was kind of what she was trained for, helping people deal with stressful situations. Okay, maybe not exactly what she was trained for, and Steve wasn't her assigned person, but she might be able to help anyway.

He grabs one of the pizza boxes and fumbles a slice out, still focused on Steve and his problem, which at least has the beneficial side effect of making his own frustration leak away a bit.