It may be regarded as taboo or unnatural, and is a criminal offense in some countries, punishable by corporal or capital punishment; by contrast, people also regard anal sex as a natural and valid form of sexual activity that may be as equally fulfilling as any other desired sexual expression. It is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual assault or domestic violence. Such films continued to be produced but could only be distributed by underground channels. 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 gay boy porn pool or a hot tub. The related term twinkle-toes, which implies that a man is effeminate, tends to be used in a derogatory manner. It may also involve touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. BDSM actions can often take place during a specific period of time agreed to by both parties, referred to as play, a scene or a session. 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 term is a slang word that originated in the gay community milf fuck and comes from the equestrian term bareback, which refers to the practice of riding a horse without a saddle. 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. But starting with The World Biggest Gangbang , starring Annabel Chong, the pornographic industry began producing a series of films ostensibly setting gangbang records for most consecutive sex acts by one person in a short period. Often a dominant woman, she may be called a Dom, Domme /ˈdɒm/, Femdomme, Domina, or Dominatrix, depending on context or personal hentai movies preference. In many cases, that person is also aroused by smelling body parts that have a urine scent.