Urolagnia is a form of salirophilia in which sexual excitement is associated with the sight or thought of urine or urination. A crush fetish is a lesbian milfs fetish in which one is sexually aroused usually when someone crushes objects, food, and sometimes small animals with their body, usually under their foot, or when crushed oneself. Interracial pornographic films have experienced an explosion in popularity, becoming one of the fastest-growing and biggest-selling genres. For example, in Australia it is rated Refused Classification . For legal reasons, the vast majority of so-called reality porn involves professional actors and actresses posing as so-called amateurs. The term hentai is never used in this context in Japanese. The reverse of videos gays this, in which nude women interact with clothed men, is called Clothed male, naked female . Female dominance refers to BDSM relationships and BDSM scenes in which the dominant partner is female. Terminology for roles varies widely within the various BDSM subcultures. A male voyeur is commonly labeled Peeping Tom, a term which originates from the Lady Godiva legend. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. Sadomasochism is practiced in isolation relatively rarely, though some masochists report biting, pinching, lesbian hentai or even stun-gunning themselves as a prelude to, or as part of, masturbation. The scenario is a genre of erotica, which on the internet is sometimes abbreviated to CMNF, and may involve sexual and nonsexual erotic scenarios. Entacle erotica describes a type of pornography most commonly found in Japan which integrates traditional pornography with elements of bestiality and a fantasy, horror, or science-fiction theme. Softcore gay pornography also exists; it at one time constituted the genre, and may be produced as beefcake pornography for heterosexual female and homosexual male consumption.