Since the 1980s, many practitioners and organizations have adopted the motto safe, sane and consensual, commonly abbreviated as SSC, which means that everything is based on safe activities, that all participants be of sufficiently sound/sane mind to consent, and that all participants do consent. 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. Some techniques which may work for one individual can be difficult or uncomfortable for another. These scenes may involve the female actor calling for the shot to be directed at some specific part of her body. The term soft crush refers to the more common fetish surrounding videos involving inanimate objects or small invertebrates being crushed, while the term hard crush refers to such videos involving larger animals with vertabrae, lesbian milfs and arguably more pain-susceptible animals . For example, in Australia it is rated Refused Classification . Women that take on the roles of the giantess within this fetish often find the practice to be empowering and enjoy being worshiped. Multiple men and women Bisexual anime hentai pornography features one woman and two men who all perform sex acts on each other. This stop and go build-up, known as edging, can achieve even stronger orgasms. A homosexual threesome would involve either three men or three women. Terminology for roles varies widely within the various BDSM subcultures. Starting with erotic stories and woodblock prints from before the 20th century, Japanese pornography evolved into distinct subcategories with the media that in addition of pornographic videos and magazines featuring live actors, there is exist categories of pornographic manga , pornographic computer gay boy porn games , and pornographic anime . Several hundred exclusively pegging films were produced, as well as twice as many bisexual and straight films with strap-on scenes. Sexual relations between women have been illustrated as well as narrated, but much of the written material from the early modern period has been destroyed.