Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. As in B/D, the declaration of the Top/Bottom may be required, though sadomasochists may also play without any Power Exchange at all, with both partners equally in control of the play. Body parts including fingers, tongue and penis may be used for anonymous oral, vaginal and/or anal intercourse. Interracial pornography typically employs ethnic and racial stereotypes in its depiction of performers and many of interracial pornographic films still include racial stereotypes, although the segregation of actors by race has diminished considerably. Actors are mostly amateur; any well-known actors in bisexual porn tend to be from the gay pornography lesbian hentai industry. Arousal may be triggered by seeing the body movements or facial expressions of that person. Performers are usually clean-shaven, thinner and more effeminate than ones in mainstream gay pornography. Anal sex or anal intercourse mobile porn sites is generally the insertion and thrusting gaysex of the erect penis into a person anus, or anus and rectum, for sexual pleasure. In some areas, there are laws stating it is not legally possible to consent to be killed, and elsewhere it may still be legally dubious . Mutual masturbation is a sexual act where two or more people stimulate themselves or one another sexually, usually with the hands. Interracial pornographic films have experienced an explosion in popularity, becoming one of the fastest-growing and biggest-selling genres. Homi Bhabha defined the idea of a racial fetish in contrast to the idea of the Freudian sexual fetish which he describes a denial of difference, where the male horny milfs sees the female as a castrated male, seeing missing parts rather than a different anatomy. Greater gaysex economic and social freedom allowed them gradually to be able to determine how they could form relationships and families.