Initially, few animation studios in the United States attempted to produce animation for adult audiences, but later examples of animation produced for adults would gain mainstream attention and success. This is why video stores might consider stocking transgendered subject matter in the straight section, as some straight men will have passive or active sex with another man as long as their partner appears to look like a woman to them, to some minor or major degree. RACK may be seen as focusing primarily upon awareness and informed consent, rather than accepted safe practices. In these cases, the appearance of an enlarged abdomen caused by obesity or overeating may be sufficient, or simply the suggestion of a protruding navel. Transwomen are most often featured with male partners, but are also featured with other transsexuals or cissexual women. Pegging is a recently invented word which features a woman gay bear porn penetrating a man with a strap-on dildo. He talked to them extensively on camera so that both he and the viewer can come to know them before any sex scenes. A large part of the popularity of these videos is seeing how regular and normal the girls are in real-life. Can also include auto-fellatio, or performing oral sex on oneself. Actors are mostly amateur; any well-known actors in bisexual porn tend to be from the gay pornography industry. Simultaneous penetration of the vagina and anus. For other scenes, particularly hentai videos in established relationships, a safeword may be agreed to signify a warning rather than explicit withdrawal of consent; and a few choose not to use a safeword at all. The effect is to give the viewer the sense that they are experiencing the sex acts that they are watching, as opposed to simply watching others as a voyeur. The fundamental principles for the exercise of BDSM require that it should be performed with the informed consent of all involved parties. Strappado with rope and a spreader bar. This type of censoring also extends to comics, video games, and milf xxx anime made for adults.