[The words are at the tip of his tongue, be careful, don't turn it towards yourself, but he holds them back, holds everything back as he watches her, careful, not quite knowing what to expect.
She wants to show him something, that much is clear. About her powers, probably - after all, isn't that what she wants him to see? That she's dangerous? She should've realized it, by now. He's dangerous, Steve's dangerous - hell, half the people in this place are dangerous. Probably over than half. Even Snow, the sweetest, most caring person he's ever met, is dangerous.
Something like that isn't gonna make him think she should be left alone.
When the gun freezes, well, that's what he expected. When she throws, it, however, he lets out an involuntary sound, a protest, don't fucking throw firearms, rule one of gun safety, but- there it goes, shattering to pieces and scattering all over the ground.]
... If your point was that that coulda been me, you shouldn't've thrown it. You wouldn't have the strength to throw me, if I was frozen solid.
[Yes, his answer is utter and complete cheek, said in a tone that is almost conversational. Sorry, Elsa, forgot you haven't met Bucky Barnes The Cheeky Shit, yet... at least not like this. Maybe in those false memories, she might recall him speaking to her like this, a few times.
It's also known as his "I don't buy your bullshit" tone.]