Some simulated sex scenes are sufficiently realistic that critics mistakenly believe that they are real, such as the cunnilingus scene in the 2006 film Red Road. 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). The last of these films, Agent 69 Jensen i Skyttens tegn, was made in 1978. 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 difference between these films and pornography is that, while such scenes might be considered erotic, the intent of these films is not solely pornographic. Although the vast majority of sexual situations depicted in mainstream cinema is simulated (in early pornography, the main actors engaged in simulated sex, with inserts placed in the film), on rare occasions actors engage in real sex. Beginning in the late 1960s, most notably with Blue Movie by Andy Warhol, mainstream movies began pushing boundaries in terms of what was presented on screen. Films showing explicit sexual activity were confined to privately distributed underground films, such as stag films or "porn loops". 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. In the film industry, unsimulated sex is the presentation in a film of sex scenes where the actors engage in a genuine sex act rather than miming or simulating the actions. ( Learn how and when to remove this template message) JSTOR ( January 2015) ( Learn how and when to remove this template message).Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. This article needs additional citations for verification.