Sex in cinema has been a topic of hot debate since the early days of Hollywood. Moralists have always objected to the amount of nudity and sexual content in films, which eventually led to the development of censorship boards and ratings systems to help control what can be depicted sexually in movies. These systems are in place today, though voluntary in most states. Despite these systems, cinema sex becomes more graphic each year, with some writers and directors pushing the boundaries. Moralists still object, but the fact remains—sex sells.

Early Censorship: The Catholic church and the Hays code brought about stringent censorship in the early days of film in the mid 1930s when the Catholi Legion of Decency led a crusade to regulate sex and violence in film. This led to the formation of the Hays code, which imposed fines on film studios that didn't comply with the regulations for decency in film. This new code forced filmmakers to find creative ways to get around code restrictions and led to the production of exploitation films such as "Sex Madness" in 1937, "The Birth of a Baby" in 1938, and "Child Bride" in 1938, which used the premise of warning against underage marriage to get the film past the stringent Hays Code. Many films of this nature were screened in theaters referred to as grindhouses (theaters normally reserved for burlesque).

Rebellion: In the early 1950s, burlesque stars began appearing in erotic films, including pin-up queen Bettie Page, who appeared in a burlesque trilogy ( "Striptease," "Varietease" and "Teaserama"), which was billed as a documentary to circumvent codes. In 1952, codes were relaxed to allow sexual material "when treated within the careful limits of good taste," though this still left room for much heated debate. The 1970s and '80s saw the rise of pornographic films that depicted graphic, no-holds barred sex, but these films, while targeted by moralists as well, have always worked outside mainstream filmmaking. Despite several court attempts to ban them, porno movies have continued to flourish.

Modern Ratings Systems: The Hays Code was abandoned by the motion picture film industry in 1968. With higher demand for graphic material in films, the industry began to integrate graphic sexual content, language and violence into more films. Film stars like Brigette Bardot, Raquel Welch and Marilyn Monroe made their careers on sensuality and sometime blatant sexuality. Shortly after the disposal of the Hays Code, the film industry imposed its own (voluntary) ratings system. The Motion Picture Association of America set ratings to be applied to films based on content and age restriction. Some of the ratings include G (general audience), PG (parental guidance) and R (restricted).

Modern Sex in Cinema: Sex in cinema is prevalent and graphic in today's films. Horror movies, art house films and even comedies often contain sexual content that borders on the graphic sexual content found in X-rated porn films. Nudity and sexuality in cinema has been thoroughly integrated into mainstream film and, while there are still moralistic objections, it appears that cinematic sex won't be going away.