The act of sexual intercourse between a man and a woman is the only human interaction capable of producing offspring, and therefore enjoys recognition in every culture as the most significant form of intimacy. Gay couples, as well as heterosexual partners, may engage in other erotic contact but this affection can’t count as consequential or as serious as intercourse. Society and law rightly give unique weight to this one form of physical contact, and pay less attention to other forms of affection or pleasure. What, after all, does it mean to “consummate” a same sex marriage? We know how to define “virgin” in heterosexual terms, but what, exactly, does that designation mean for lesbians or gay males? The effort to erase all distinction between man-woman sex and gay relationships contradicts both nature and common sense.