An orgy is a gathering where guests freely engage in open and unrestrained sexual activity or group sex; and a bunga bunga orgy is an orgy in which participants have sex underwater, such as in a swimming pool or a hot tub. Bhabha, Anne McClintock momsex and Kobena Mercer. Insertion in pornography features women inserting hentai sex various odd objects into their anus or vaginas. Each participant may engage in any type of sex acts with one or both of the others, such as vaginal, anal or oral sex or mutual masturbation. Such explicit sexual interaction is seen only rarely in public play spaces, and it is sometimes specifically banned by the rules of a party or playspace. 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. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. The current record is held by Lisa Sparks who had sex with 919 men on October 16, 2004 in Warsaw, Poland as gay sex video part of the Third Annual World Gangbang Championship and Eroticon 2004. Other possibilities are possible, such as a man having sex with two women who are having sex with each other. Mutual masturbation is a sexual act where two or more people stimulate themselves or one another sexually, usually with the hands. 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. Individuals who can change between top/dominant and bottom/submissive roles—whether from relationship to relationship or within a given relationship—are known as switches, though the term switch in this context is occasionally seen as derogatory and is rejected by many who might simplistically fit the definition. Originating in Japan in the 1980s, the genre subsequently spread to North America and Europe, and crossed over into gay pornography.