[Bucky has a point, but it's not one Bruce applies to himself.] I don't think I could work like that, [he admits, less like he's disagreeing and more like he's acknowledging one of his own limitations.] I can't-- do that. Walk off, after I commit to something.

[Part of his resistance here is based in how seriously Bruce takes his commitments. He's all or nothing. If he agrees to be part of the Avengers, he's in it, full force, no reservations. That's a big reason he hasn't really agreed.]

No, you should-- hold on. Our group has definitely shrunk around here. [Bruce shakes his head.] And thanks, but I don't need any head knocking. [He can enforce his own boundaries, that's for certain.]