Others may also use vibrators and other sexual devices more commonly associated with female masturbation. Squirt pornography involves momsex women ejaculating. In addition to mainstream pornography, the popularity of facials has led to creation of its own niche market, like video series that specialize in showing the act. The term soft crush refers to the more common fetish surrounding videos involving inanimate anime hentai objects or small invertebrates being crushed, while the term hard crush refers to such videos involving larger animals with vertabrae, and arguably more pain-susceptible animals . The first pegging scene appears to have been in the non-pornographic 1970 film Myra Breckinridge, based on the novel of the same name by Gore Vidal, although it was not explicit. Depictions of male and female masturbation are common in pornography, including gay gay twink porn pornography. Gloryhole pornography features women performing fellatio on unidentified men through a small hole made in a bathroom divider. Group sex is sexual behavior involving more than two participants. A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio. Matsuo used amateur actresses in his videos, and he usually traveled to their hometowns for the filming. Pegging is a sexual practice in which a woman performs anal sex on a man by penetrating the man anus with a strap-on dildo. The consent and compliance for a sadomasochistic situation can be granted only by people who can judge the potential results. The term is a slang word that originated in the gay community and comes from the equestrian term bareback, which refers to the practice of riding a horse without a saddle. Transsexual people Transman pornography features performers who were born female and who medically transitioned to male. As of 2013, little analysis of this paraphilia has been reported in medical literature. Can also include auto-fellatio, or performing oral sex on oneself. Interracial pornography typically employs ethnic and racial stereotypes in its depiction of performers and many of interracial pornographic films still include racial stereotypes, although the segregation of actors by race has diminished considerably.