Some techniques which gay sex video may work for one individual can be difficult or uncomfortable for another. Some may keep their hand stationary while pumping into it with pelvic thrusts in order to simulate the motions of sexual intercourse. Transgender pornography features performers who cross-dress for sexual gratification, either for themselves or for their partners. Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having big tit milf sexual intercourse with female characters. These agreements are binding in the sense that the parties have the expectation that the negotiated rules will be followed. The definition clash also appears with the English definition of yuri as any lesbian relationship, as opposed to its sexually explicit definition in Japan. As of 2013, little analysis of this paraphilia has been reported in medical literature. 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, and arguably more pain-susceptible animals . Transsexual porn star Wendy Williams has stated that transsexual Porn is classified as Straight Specialty. Sigmund Freud considered foot binding as a form of fetishism. Because the viewing of such films carried a social stigma, they were viewed at brothels, adult movie theaters, stag parties, at home, in private clubs and also at night cinemas. A sub-set of vaginal fisting attempts hentai sex to photograph the female cervix immediately after the fist is removed from the now-gaping vagina. Bestiality is illegal in many countries. Femdom features BDSM scenes in which the dominant partner is female. Mutual masturbation can be practiced by males or females in pairs or groups with or without actually touching another person as indicated by the following examples of contact versus non-contact scenarios: Non-contact mutual masturbation Two people masturbating in the presence of each other but not touching.