The stimulation may involve hands, fingers, everyday objects, sex toys or combinations of these. To tea bag is a slang term for the sexual act of a man placing his scrotum in the mouth of a willing sexual partner for pleasure or onto the face or head of another person. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions momporn of interracial sexual activity. The first pegging scene appears to have been in the non-pornographic 1970 film Myra Breckinridge, based on the novel of the same name by Gore Vidal, although it was not explicit. Am Abend , one of the earliest pornographic films that have been collected at the Kinsey Institute lesbian hentai for Research in Sex, Gender, and Reproduction, starts with a female masturbation scene. Enema pornography involves adults given enemas to others, often fake. Participants usually derive pleasure from this, even though many of the practices—such as inflicting pain or humiliation or being restrained—would be unpleasant under other circumstances. Bukkake, Gokkun, Omorashi, and tentacle erotica gay bear porn are few uniquely Japanese genres known to western viewers. The fundamental principles for the exercise of BDSM require that it should be performed with the informed consent of all involved parties. Some BDSM practitioners prefer a code of behavior that differs from SSC and is described as risk aware consensual kink , indicating a preference for a style in which the individual responsibility of the involved parties is emphasized more strongly, with each participant being responsible for his or her own well-being. Various groups within society have considered depictions of a sexual nature immoral, labeling them pornographic, and attempting to have them suppressed under obscenity and other laws, with varying degrees of success. It is also often mixed with other fetishes in practice, such as voyeurism, denial, etc. Bobbi S. Fisting pornography features the insertion of an entire hand into a performer vagina or anus.