A threesome is also depicted with one woman and two men who all perform sex acts on each other . Tentacle erotica features tentacled creatures raping or otherwise penetrating women or men. The 1999 William Higgins production Double Czech included actual sex between the Bartok twins, as did the 2009 sequel between the Richter twins, though the Bartok brothers were described as looking utterly mortified in their scene. Point of view pornography is adult entertainment filmed to look as if the watcher were experiencing the sex act themselves. Sadomasochism refers to the aspects of BDSM surrounding the exchange of physical or emotional pain. The most successful animated features produced in the United States primarily for adult audiences were directed by Ralph Bakshi, including Fritz the Cat, Heavy Traffic and Coonskin. Matsuo started working in the genre in 1991, saying that this intimate technique was a natural way for him to shoot in order to show his feelings for the girl and to get her to open gay cock up about herself, to show her true emotions. Jeffrey Masson has even argued that incest porn is the very nucleus of pornography — its prototypical form. Men with Women, Women with Men Heterosexual or traditional porn accounts for the majority of produced film and video content in the industry. Activities range from a spontaneous smack on bare buttocks during a sexual activity, nude milfs to occasional sexual roleplay, such as ageplay, to domestic discipline and may involve the use of a hand or the use of a variety of spanking implements, such as a spanking paddle or cane. Creampie, also known as internal cum shot, and, in homosexual contexts, also known as breeding and seeding, is a slang term used in pornography to describe when a male ejaculates inside his partner hentai sex vagina or anus. In general, as compared to conventional relationships, BDSM participants go to great lengths to negotiate the important aspects of their relationships in advance, and to take great care in learning about and following safe practices.