That repetitive huffing sound? Definitely amusement on Bucky's part. Laughter, even, as Bucky bares his teeth without even growling, ears up and alert. See? He has them too. He also looks Sam in the eye and shakes his massive head, left to right. No, he will not be pulling out tonight, so sorry Sam.

Bucky leans forward. Shifts his weight in the chair, just a bit, tilting his body and Sam's along with it in the direction of the desk. Puts his chin on Sam's shoulder and one claw out against the wooden surface of the desk.

And bounces Sam again.