Why wear shoes? Why wear stockings? Why wear corsets? Why wear anything? Why aren't girls always totally butt-ass naked in every porn scene?!?!?!?
Because keeping some clothing on adds to the fantasy that the girls just want to fuck right-fucking-now and can't be bothered to get totally undressed.
Because keeping some clothing on adds to the fantasy that the girls just want to fuck right-fucking-now and can't be bothered to get totally undressed.