Japanese rope bondage is distinguished by its use of specific katas and aesthetic gaysex rules. 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. Anti-pornography psychologist Ana Bridges and colleagues conducted a content analysis of best-selling heterosexual lesbian hentai pornographic videos showing that over 96% of all scenes concluded with a male performer ejaculating onto the body of his female partner. Exhibitionist pornography features performers, usually female exposing themselves in public and spans simple flashing to public sex. Scenes of multiple penetration are common in pornography. Also see POV. Sometimes, asymmetric and often intentionally uncomfortable positions are employed to heighten the psychological impact of the bondage. A smotherbox has two openings. Yaoi : Featuring two grown adult men in a homosexual/gay relationship. As with most forms of sexual activity, anal sex participants risk contracting sexually transmitted infections . For other diaper fetishists, simply wearing a diaper, the bulking feeling and crinkling sounds associated with it, is enough to cause the fetishist a form of erotic pleasure or sexual arousal. Seconds after being deposited onto the face, the semen thickens, before liquefying 15–30 minutes later. 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. Erotic spanking is the act of spanking another person for the sexual arousal or gratification of either or both parties. It is distinguished from these concepts in that the cuckold thrill in their partner acts is specifically masochistic; as such it is considered a category of BDSM fetish.