Mutual masturbation, mutual manual big tit milf stimulation of the genitals between partners, can be a substitute for sexual penetration. Concerted deployed sexual rejection exercised on the partner can be an aspect of Dominance and Submission as well. The current public acceptance of celebrities with sex tapes is speculated by Joe Levy, executive editor of Rolling Stone, to be due to the easy availability of pornography, as well as couples more commonly making their own tapes due to the prevalence of video cameras. Some aspects of the research community distinguish between female ejaculation and what is colloquially known as squirting or gushing. It has since become popular enough with couples to be discussed during an episode of Sex and the City. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. 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. They may be noted for using risqué themes, graphic violence, sexuality or black comedy in a manner that is unsuitable for younger audiences. While wearing diapers, a diaper fetishist gay twinks generally experiences a comforting feeling. Studies have found that masturbation is frequent in humans of both sexes and all ages, although there is variation. In the 18th and 19th centuries, some European theologians and physicians described it as heinous, deplorable, and hideous, but during the 20th century, these taboos generally declined. Point of view pornography is adult entertainment filmed to look as if the watcher were experiencing the sex act themselves. Reality pornography is a genre of pornography where hentai porn staged scenes, usually shot in cinéma vérité fashion, set up and precede sexual encounters. Mammary intercourse has sometimes been considered a perversion. Some anthropologists and sociobiologists believe that breast fetishism derives from the breasts similarity to buttocks, but instead provide sexual attraction from the front of the body.