He knows that Bruce might not forgive him for going this far. It's a push he wasn't ready for, and that can end up hurting him as much as helping. But he truly believes he can help Bruce across that barrier he's put up, and damn it, he's going to help him no matter what it takes. So he doesn't pull back even when he hears the attempt to protest.

He swallows that moan with his mouth over Bruce's. His tongue strokes his friend's, teasing, urging him to respond to the kiss by prompting hot friction. And his hand doesn't stop either. When Bruce thrusts, he holds them together, letting him thrust against his cock and between the loop of his fingers. The more friction the better.

Bruce looks amazing like that. Eager and caught up in his arousal, and Tony lets his fingers play at the tip of his cock, stroking the head so he can add even more stimulation to the moment. There's no real stopping now, and he wants it to feel as good as he can make it. At least before Bruce comes to his senses again.