The rare instances where actors actually perform the real deal.

10. Caligula, 1979. Caligula was based on the real life exploits of the notoriously insane and lustful Roman Emperor and featured plenty of group sex, including penetration, fellatio and ejaculation.The film is called one of the most obscene mainstream movies ever, and IMDb’s Parental Guide states that “No child should ever watch it, and several adults will have trouble with it. The film’s sexual content is considered pornographic in nature, with several hardcore inserts intended to sexually arouse, but really turn out to be quite disturbing.”