Bruce realized in the moment that Clark was pushing him back that he didn't know what he was supposed to do here. When he pushed buttons to make things happen - or when it just happened by unspoken agreement and it wasn't someone he loved - he knew how to do it.

With those new factors in play, he didn't. Did he just fall back? Did he resist? Did he fight with Clark about it? Would that turn Clark off? Would that be the opposite of helping Clark? Those barely scratched the surface of what went on his brain during period between Clark returning the kiss and Bruce's back hitting the mattress.

Ultimately, he was so busy with the gears in his mind turning that he didn't resist at all. When the hand went to his throat he did. Sort of - he reached up and grabbed at Clark's wrist instinctively, and he snarled. Not fear, though, no just arousal and need, tangled up with the instinct to fight anyone who had him in that position.

And he ... was still trying to find answers. Doing would probably provide them but he was watching the hell out of Clark. Not out of mistrust but because he desperately wanted to be helping Clark - or for at least this not to damage him.