This article is about sex; but not about sex meaning gender, an adjective, or “that thing we are.” It is about sexual behavior. It is, in Professor Franke's words, about sex as verb--“that thing we do”--or, to quote Judge Posner, it is about that “quintessential private activity [of] our culture.” However, it does not focus on sex as “the ultimate animal necessity.” That would be the realm of today's talk shows headed by Jerry Springer and his ilk. Instead, it focuses on the pervasiveness of sexual discourse in the legal realm and tries to explain the reason behind it. This article suggests that sex has become a human behavior that is often legally sanctioned because it offers itself to endless and various permissive and restrictive regulat...