Mammary intercourse is a sex act, performed as foreplay or as non-penetrative sex, that involves the stimulation of the male penis by the female breasts and vice versa. In some scenes or relationships it may be impossible for consent to be withdrawn in the middle of a scene, or the bottom may have the ability to revoke consent for a relationship as a whole, gaysex but not for a particular scene. In academic discourse, racial fetishism is a postcolonialist term found in the writings of authors such as Homi K. A homosexual threesome would involve either three men or three women. If this is done using penises and/or strap-on dildos, this is sometimes called the sandwich or BigMac. Voyeurism: Seeing another urinate without the person knowledge either through video taping by a hidden camera, or by lurking in locations where people are urinating or are likely to have an urge to lesbian hentai urinate. Female dominance refers to BDSM relationships and BDSM scenes in which the dominant partner is female. 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. Rape pornography features performers simulating rape. Babysitter pornography features usually teenage girls being exploited and having taboo sex with older, male employers. Pornography is often distinguished from erotica, which consists of the portrayal of sexuality with high-art aspirations, nude milfs focusing also on feelings and emotions, while pornography involves the depiction of acts in a sensational manner, with the entire focus on the physical act, so as to arouse quick intense reactions. The reverse of this, in which nude women interact with clothed men, is called Clothed male, naked female . Women porn is often produced by women and aimed specifically at the female market - rejecting the view that men are turned on by porn but women only by a box of chocolates. 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.