Common positions include lying on back or face down, sitting, squatting, kneeling or standing. Common phrases used to refer to these individuals are chicks with dicks or the derogatory term shemale, although these are generally considered pejorative among transwomen. Mutual masturbation, mutual manual stimulation of the genitals between partners, can be a substitute for sexual penetration. Buttocks are sometimes emphasized in pornography, where they are often referred to as booty. Individuals are also sometimes abbreviated when referred to in writing, so a dominant person may be referred to as a Dom for a man, and a Domme for a woman. Foot fetishism has been defined as a pronounced sexual interest in the feet or footwear. A related term used in the genre is the term cougar, which implies porn milf an older woman as predator. Cuckold fetish pornography that celeb sex tapes involves a cuckolded 3d hentai husband. Bondage/BDSM Bondage pornography features performers tied up or constrained in various ways. In the gay pornography industry, which uses amateurs as well as professional actors, the term gay-for-pay gay movies refers to actors labeled or believed to be straight but who engage in same-sex sexual activities for money. Femdom features BDSM scenes in which the dominant partner is female. Types of anal sex can also be a part of lesbian gaysex sexual practices. 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. The name is a reference to gonzo journalism, in which the reporter is part of the event taking place. Interactive pornography, available in CD-ROM and DVD format, allows the viewer to select the particular acts performed at any one time, sometimes with the camera providing a first person view. Masturbation is the self-sexual stimulation of the genitals for sexual arousal or naked celebrities other sexual pleasure, usually to the point of orgasm. In general, BDSM play is usually structured such that it is possible for the consenting partner to withdraw his or her consent during a scene; for example, by using a safeword that was agreed on in advance.