These agreements are binding in the sense that the parties have the expectation that the negotiated rules will be followed. 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. Transsexual porn star Wendy Williams has stated that transsexual porn is classified as Straight Specialty. Depictions of male and female masturbation are common in pornography, including gay pornography. Usually that person prefers to stage the wetting hentai sex so that his/her legs become soaked with urine. Transsexual pornography young gay porn is a genre of pornography. This stop and go build-up, known as edging, can achieve even stronger orgasms. Guro or Gore is a genre of Japanese pornography involving blood, gore, disfiguration, big tit milf violence, mutilation, urine, enemas, or feces. Other possibilities are possible, such as a man having sex with two women who are having sex with each other. BDSM is a variety of erotic practices involving dominance and submission, role-playing, restraint, and other interpersonal dynamics. Lucky Pierre is slang for a person performing both receptive and insertive anal and/or vaginal sex simultaneously during a threesome, being positioned between the two partners. The work of Bruce Seven has been called reality porn, due to his lack of using scripts and asking his performers to act naturally in their own character. Advocates of RACK argue that SSC can hamper discussion of risk because no activity is truly safe, and that discussion of even low-risk possibilities is necessary for truly informed consent. Sexologist Alfred Kind suggested that the buttocks is the primary sexual presentation site in primates. Pornography in the early 2000s. Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having sexual intercourse with female characters. A male voyeur is commonly labeled Peeping Tom, a term which originates from the Lady Godiva legend.