With a huff, Steve tilts his head at an angle Bucky is probably the most familiar with. It’s Steve’s usual ‘I smell bullshit’ stance, and the upturn of his lips probably give that away. His smile is soft, though, and never falters even when Bruce takes his blood. “You smell sour. Not body odor sour or sick sour. Just— You’re not human.” He doesn’t know why he’s put it that way but it’s slipped out already and he can’t just take it back. It feels right on his tongue anyway. Bruce Banner isn’t human. Or not entirely so.

That should scare him, but it doesn’t. It makes him want to puff up his chest, stand, and try to fight for dominance. He doesn’t, he still had his faculties about him, but his posture’s shifted towards Bruce. Knowing, sure, but annoyingly smug too.

“I’ve always thought that there’s got to be aliens here. The universe is too big... I just didn’t think I’d meet one.”