i like having my face slapped--but not by anybody. I agree with Arria on this one, if the wrong person does it, he gets kicked in the balls, end of story.
And it does make me cringe, even from the 'right' person, but in a nice tingly kind of way. It also scares me in a nice context, I feel that rush of adrenaline I get when whipped or choked.
But, then again, that's just me.