On a night your guy is coming over to hang out, masturbate alone just before you're going to see him, but don't let yourself climax. To bring yourself right to the edge without going over, close your eyes and imagine your guy's lips taking the place of your hand. Squeeze your PC muscles for a count of five as you massage your clitoris, then stop moving. Stay naked until he shows up, and let him see the flush that naturally spreads over your body as you near orgasm. Then describe for him what you've been up to. He'll put together an irresistible mental image of you self-pleasuring that will build his desire so that when you have sex, it'll be an incredible release for you both.