i love this kind of foreplay almost as much as the act itself. once in a while i have my boyfriend walk around in his underwear, or a certain pair of flimsy pajama pants he has, and its pretty sexy watching his soft bulge move around as you can clearly see his length and shape of the head area. I also ask him to walk up and down the room nude as I can see him dangling even with his back to me, which for some reason is quite the turn on.