"Don't you Dare..."

"You do know, ____ is a punishable offence?"
(especially sexy when the ____is something I believe to be none of his business...)

"We'll see about that."
(when I tell him something I want, and he's on top, much better than a plain yes or no...makes it more rewarding and exciting if I end up getting what I want)

and I love it when he calls and simply say "What are you doing?" it is all in his tone and my sense that he is...examining my actions.