Dogging is a British English slang term for engaging in sexual acts in a public or semi-public place or watching others doing so. The term hamedori came into use about 1988–1989, but it was only a small niche area until it was popularized at V&R Planning by director Company Matsuo. One-sided male nudity can also arise when a male disrobes as part of a male striptease. The term bareback is used less frequently in the heterosexual community. Fisting involves the insertion of one partner entire hand into a vagina or the anal cavity. This is not due to a medical need. Technically this is a form of exhibitionism rather than group sex per se. Bestiality pornography involves momsex the sexual attraction of humans to animals. In the 1920s, Havelock Ellis reported that turn-of-the-century seamstresses using treadle-operated sewing machines could achieve orgasm by sitting near the edge of their chairs. The speed of the hand motion will vary from person to person, although it is not uncommon for the speed to increase as ejaculation nears and for it to decrease during the ejaculation itself. Fistees who are more experienced may take two fists . The surfacing of sex tapes has become so common that some are leaked as a marketing tool to advance or establish a media career. Gang bang pornography is a type of pornography that depicts an individual engaging in physical sexual activity with videos porno gay multiple partners sequentially or at once. Gaping in pornography refers to scenes of anal sex with a focus on the recipient’s anus remaining open for a period of time after the erect penis or dildo is removed. A large part of the popularity of these videos is seeing how regular and normal the girls are in real-life. The anal and rectal tissues are delicate and do not provide natural lubrication, so they can easily tear and permit hentai movies disease transmission, especially if lubricant is not used. 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.