In the film industry, unsimulated sex is the presentation of sex scenes in which actors genuinely perform the depicted sex acts, rather than simulating them. Although it is ubiquitous in films intended as pornographic, it is very uncommon in other films. At one time in the United States, such scenes were restricted by law and self-imposed industry standards such as the Motion Picture Production Code. Films showing explicit sexual activity were confined to privately distributed underground films, such as stag films or "porn loops". In the 1960s, social attitudes about sex began to shift, and sexually explicit films were decriminalized in many countries.
With movies such as Blue Movie by Andy Warhol, mainstream movies began pushing the boundaries of what was presented on screen. Notable examples include two of the eight Bedside-films and the six Zodiac-films from the 1970s, all of which were produced in Denmark and had many pornographic sex scenes, but were nevertheless considered mainstream films, all having mainstream casts and crews and premiering in mainstream cinemas. The last of these films, Agent 69 Jensen i Skyttens tegn, was made in 1978. From the end of the 1970s until the late 1990s it was rare to see hardcore scenes in mainstream cinema, but this changed with the success of Lars von Trier's The Idiots (1998), which heralded a wave of art-house films with explicit content, such as Romance (1999), Baise-moi (2000), Intimacy (2001), Vincent Gallo's The Brown Bunny (2003), and Michael Winterbottom's 9 Songs (2004). Some simulated sex scenes are sufficiently realistic that critics mistakenly believe they are real, such as the cunnilingus scene in the 2006 film Red Road.
