NEW HAVEN, Conn. - In a lecture hall on Yale’s storied Old Campus, not long after an afternoon astronomy class has cleared out, a middle-aged sex toy saleswoman demonstrates her technique and hands out free products to an eager crowd. “I want you to close your eyes,” Patty Brisben playfully instructs a young man as she rubs scented lotion into his forearm and, to raucous laughter, reaches for an electric toy and a glove. “Fantasize about having an all-over body massage.” Welcome to Sex Week at Yale, a biennial celebration that has become one of the most provocative campus events...