What do princes do when the hot weather hits? They play! For William, 22, that means snorkeling, motorbiking and soaking up the sun on the small island of Rodrigues in the Indian Ocean. British papers speculate girlfriend Kate Middleton, 22, was among the group f of pals vacationing with him. Meanwhile Harry, 19, is honing his playboy image, flirting his way through England's high-society haunts. For the two brothers, says royal watcher Judy Wade, "it has been a summer of fun."