Although interracial pornography theoretically can apply to depictions of sexual activity between performers of any different racial groups, the term is most commonly used for heterosexual sex acts between black and white performers. The object or situation of interest is called the fetish; the person who has a fetish for that object/situation is a fetishist. It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is 18. Women oriented pornography is sometimes referred to as sex positive pornography. A variant of A2M is ATOM where a performer inserts his penis directly from one recipient anus into a second recipient mouth. Detective magazines, comic books and early fetish magazines In the early 20th century, Detective magazines covertly provided a way of publishing bondage imagery. Clothes wetting: The person is sexually aroused by wetting one clothing or observing another person doing so. A sub-set of vaginal fisting attempts to photograph the female cervix immediately after the fist is removed from the now-gaping vagina. Tentacle erotica can be consensual, but frequently contains elements nude milfs of non-consensual sex. In S/M, the Sadist is usually gay cock the Top and the Masochist the Bottom, but these roles are frequently more complicated or jumbled . If dramatic skills are not involved, a performer in a porn film may also be called a model. Jerk off instruction features a performer encouraging or instructing the viewer to masturbate, often culminating in a countdown at the end of which the viewer is invited to induce orgasm. Diaper pornography involves performers wearing diapers, sometimes with an adult performer acting in the role of a caretaker. Some techniques which may work for one individual can be difficult or uncomfortable for another. Multiple men and women Bisexual pornography features one woman and two men who all perform sex acts on each other. Oral sex pornography frequently features a person anime hentai performing fellatio, and less frequently cunnilingus.