The flareup of irritation passes as Tony draws his attention again, and the Hulk hums back, though it's really more of a rumble. He doesn't have much experience at all, but some things are filtering in from Banner's end, probably drawn out by the familiar taste and feel of Tony in the first place. He parts his lips, inviting Tony to do what he likes. The Hulk trusts him completely, no reservations.

It's nice to have that with someone, and he's glad that person is Tony, besides. He can give his loyalty to anyone who's deserving of it, but Tony is so fun and kind, and when he looks at the Hulk, the Hulk doesn't feel like he's something different or strange.

He's starting to get lightheaded, but he attributes it to the kiss, what he notices of it at all.