Barring actual adult films, many sex acts depicted in films are simulated, meaning the actors and actresses are just doing what it is they do best: acting! It is very rare for a mainstream film director to ask his actors or actresses to have actual sex or engage in actual sex acts on camera and in front of the rest of the cast and crew. Some actors and actresses won't even do a nude scene even when the part calls for it. See: Jessica Alba as Nancy in Sin City.
However, just because something isn't a norm, doesn't mean there aren't exceptions to the rule. Sometimes a director and the actors have a mutual understanding and want the film to look and feel as organic as possible. On these rare occasions, real sex and sex acts are sometimes used on screen. Let's take a look at a few of these films now.
WARNING: Some of these descriptions are not for the faint of heart or the easily offended. Proceed with extreme caution.
10 Caligula (1979)
This film from writer Gore Vidal and director Tinto Brass was never actually supposed to contain any real sex. The film was co-produced by Bob Guccione who was responsible for the publication of Penthouse magazine and similar publications. Guccione eventually fired Brass for running up huge costs and took control of the film himself. This resulted in Guccione splicing in segments of explicit sex scenes instead of segments written by Vidal or filmed by Brass. That is not to say that Vidal and Brass had a cleaner film, as it's alleged that Guccione used these scenes as opposed to disturbing sexual imagery filmed by Brass.
The result is one of the most popular cult films to date.
9 Cruising (1980)
William Friedkin both wrote and directed this film about a police officer that goes undercover into the underground world of gay S&M and leather bars in an attempt to find a serial killer that has been targeting gay men and and throwing their body parts into the Hudson River. The film was originally given an X-rating and Friedkin had to cut nearly 40 minutes from his product to achieve an R-rating. It is said that the footage removed was some of the most graphic simulated homosexual sex caught in a mainstream film. Despite cutting the simulated sex from the film, Friedkin had spliced opening scenes of violence with actual sex that somehow made it by the MPAA.
Many gay men tried to keep the film from being released due to its negative portrayal of gay men; a group that was already falling victim to extreme prejudices in the 1980's.
8 The Brown Bunny (2003)
This film written, produced, directed, and starring Vincent Gallo was said to be "the worst film to ever come out of Cannes" by film critic Roger Ebert, though he later redacted the statement when he saw a different edit at a Toronto Film Festival.
The final scene in the film features an actual scene of Sevigny performing fellatio on Gallo, an act she didn't initially see as a big deal since she had been intimate with Gallo before. Several years later, Sevigny said that there is a lot of emotion tied up into the scene that she may one day need therapy for. She also says she's not interested in doing explicit sex scenes again.
7 8MM 2 (2005)
Starring: Johnathon Schaech and Lor Heuring
This film from director J.S. Cardone was originally titled The Velvet Side of Hell. For whatever reason, when Sony picked up the rights they decided to rename the film 8mm 2, suggesting that it was a sequel to the 1999 Nicolas Cage flick. This was definitely not the case for this direct-to-dvd flop.
This film about a diplomat and his fiancee tracking down a blackmailer that caught them having a threesome features many explicit sexual scenes. Many of these acts are unsimulated and in addition, Cardone spliced in actual scenes from adult films.
6 6. Antichrist (2009)
Starring: Charlotte Gainsbourg and Willem Dafoe
You really couldn't have a list like this without Lars von Trier appearing somewhere on it. We could have added a number of films from Lars von Trier, but we'll keep it at one for the sake of diversity.
In Antichrist, a man and woman are in the throes of passionate love-making while their young son falls from a window while unattended. According to Lars von Trier, the sex in this scene is 100% real. However, the couple being filmed is not Willem Dafoe or Charlotte Gainsbourg, who won best actress for the film at the 2009 Cannes Film Festival. The real sex in the scene was achieved through the use of two body doubles filling in for Gainsbourg and Dafoe.
5 Pink Flamingos (1972)
Starring: Divine and Mink Stole
In this celebration of pure "trash cinema" from director John Waters, the Marble couple is trying to steal the tabloid given title of "The Filthiest Person Alive" from a local drag queen named Divine. Many strange and gruesome sex acts are actually depicted in this film, the most forward sex act however is with Divine and her son. While the scene is indeed real, Crackers is not actually Divine's real son.
4 El Topo (1970)
Starring: Alejandro Jodorowsky
There is a scene of rape in the film and according to Jodorowsky in a DVD special feature interview, the sex in the scene is 100% real. Jodorowsky claims that they found the actress playing the woman wandering the streets aimlessly, drunk, and on about "500 hits of acid." It would seem she was all too willing to do just about anything on camera, so the director and other cast members just went along with it to keep the scene as organic as possible.
How much in her right mind the woman was during the scene is unknown.
3 Alice in Wonderland (1976)
Starring: Kristine DeBell
Believe it or not, there was an Alice in Wonderland film that featured real sex, but it wasn't exactly what you might think.
Obviously Disney was not involved as the Disney version is only one of numerous interpretations of the Lewis Carroll classic. This 1976 version was actually filmed as XXX film first, but since it was unique as an "adult musical comedy" the more graphic and extreme elements were edited out of the film so it could get a standard release as well.
Since this flick was initially filmed as an XXX film, you can be assured that nearly all the sex in the film is 100% real.
2 Enter the Void (2009)
Starring: Nathaniel Brown and Paz de la Huerta
This trippy, mind-bender of a film from director Gaspar Noe is a must see for any cinephile; it's absolutely gorgeous.
The entire film is shot in first-person from the perspective of a dead drug dealer whose soul is witnessing the succeeding events from his death as a "fly on the wall." Naturally this perspective would have to confront seeing people at their most exposed to be truly effective. The film definitely succeeds in this as it goes so far as to show actual close-up scenes of sex.
1 9 Songs (2004)
Starring: Kieran O'Brien and Margo Stilley
This film from director Michael Winterbottom is a romantic drama film following a 12 month relationship between a man and a woman that meet at a rock concert. Each scene is set to 9 different live songs from 9 different bands, and paired with live concert footage for each of the different songs. Some of the bands included are Franz Ferdinand, The Von Bondies, Primal Scream, and The Dandy Warhols. In each of these scenes, the lead actor and lead actress engage in sexual acts, and all of these acts were totally real and unsimulated.