My high school girlfriend used to do a little trick that always make me rock hard. While having dinner at a restaurant, she would fantasize at the table and lightly touch herself. Once she was turned on, she'd head to the ladie's room where she would rub herself - but not bring herself to orgasm. She'd return to the table and have me kiss her hand, so I could get pick up the scent of her wet pussy.

Hey waiter, can you bring the the check?!