MARY J. BLIGE stunned fans during a recent U.S. TV show appearance by candidly confessing she's a member of the Mile High Club. The R+B superstar was answering personal questions on pal Tyra Banks' talk show when the subject turned to Blige's sex life. Asked if she'd ever made love on an airplane, the stunned I'm Going Down singer hesitated, before answering, "Yeah." But Blige refused to elaborate - to spare the blushes of her husband of four years, Kendu Isaacs. Despite Blige's desperate pleas to change the subject, nosy Banks asked, "Was it in the toilet? On a private or commercial jet?" The chuckling singer said, "I'm married now, let's move on."