Too bad guys can't wear one of those pocket crochet snatches discreetly like girls can wear their little secret, wearable vibrators. Of course, even if there wasn't the problem of concealing the hard-on, you'd have to come up with some way to make it "suck" or glide back and forth... slow vibrate.. and then feel wet and warm... feel like flesh... otherwise it'd just be a cock sweater...