A frustrated sound breaks out of him before Bucky can register that he's going to do it, or restrain it. He looks surprised for a second before clamping down, his gaze lowering. It's no help at all, like he knew it wouldn't be because he doesn't know how to do that, even with being told.

It would be so much simpler if Steve would just tell him what to do.

... but then does he really want to go back to that life of blindly following, even with someone like Steve giving him the orders? No. This is him railing against something he can't help but perceive as a failure, no matter how many assurance he's given to the contrary. He is losing track of why he came here.

"I want," Want is such a monumental word, "to help you."