He smiles, pleased that wasn't a fight; don't get him wrong, he generally likes it when Tony pushes him, the most anyone can ever like being pushed out of their comfort zone, but in this area... he'd really rather not risk too much. He thinks he can attribute some of that to Tony's influence. Of course there's the obvious part where he doesn't want to Hulk out and hurt Tony, but he also just really, really wants this, to lose himself to this as much as he can safely. Keeping his self control is more about having this than not.

"Baby steps on the fun. I haven't had this much in a while. Don't want me to get overexcited and ruin the whole party so soon, right?" He smirks, and he dips his finger inside Tony's waistband, dragging it along until he gets to his fly. His eyes on Tony, watching closely, the heat burning just beneath the surface, he undoes the button and slips his hand inside. His fingers trace the shape of his cock through the fabric, and Bruce's breath hitches to feel the heat of him.

Bruce's seduction methods are far more slower than Tony's. They're about letting the heat build until he can't stand it anymore, until it nearly breaks him; while he loves that Tony just goes after what he wants, there's a part of him that wants to watch Tony squirm.