Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. The initialism BDSM includes psychological and physiological facets: Bondage & Discipline Dominance & Submission Sadism & Masochism Types of Play This model for differentiating among these three aspects of BDSM is increasingly used in literature today. The two sets of people involved often meet either randomly or arrange to meet up beforehand over the Internet. When used as an alternative to penile-vaginal penetration, the goal may be to preserve virginity or to prevent pregnancy. In the gay pornography industry, which uses amateurs as well as professional actors, the term gay-for-pay refers to actors labeled or believed to be straight but who engage in same-sex sexual activities for money. In the West, masturbation in private or with a partner is generally considered a normal and healthy part of sexual enjoyment. Point of view pornography is adult entertainment filmed to look as if the watcher were experiencing the sex act themselves. In POV porn, the shooting style is generally similar to gonzo pornography, with the person receiving sexual gratification holding the camera him or herself—aiming it down at the actress or actor who is performing the sex act. Some masturbate only using pressure applied to the clitoris without direct contact, for example by pressing the palm or ball of the hand against underwear or other clothing. Sadomasochism refers to the aspects of BDSM surrounding the exchange of physical gayporn or emotional pain. The fantasy is typically based around one or more larger beings dominating a smaller being. Breeding is sometimes followed by felching, which involves sucking the semen from the partner anus. New York photographer Irving Klaw also published illustrated adventure/bondage serials by fetish artists Eric Stanton, Gene Bilbrew, Adolfo Ruiz and others. 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.