It is commonly depicted in pornography, but very rarely in mainstream cinema. Related genres include: Amateur pornography originally referred only to pornography produced by amateurs but now also includes professionally made pornography designed to appear as if it were amateur. The scenario is a genre of erotica, which on the internet is sometimes abbreviated to CMNF, and may involve sexual and nonsexual erotic scenarios. Interracial pornographic films have experienced an explosion in popularity, becoming one of nude milfs the fastest-growing and biggest-selling genres. A few extremely flexible males can reach and hentai videos stimulate their penis with their tongue or lips, and so perform autofellatio. The anus has a relatively high concentration of nerve endings and can be an erogenous zone, and the receiver may receive pleasure from external anal stimulation. There may be more than two participants; both group sex and gang banging can be included. The consent and compliance for a sadomasochistic situation can be granted only by people who can judge the potential results. Real enema shots or videos of true medical situations may violate privacy laws in some countries. 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. Female ejaculation is the expulsion of fluid by the paraurethral ducts through and around the human female urethra during or before an orgasm. The stigma of being gay or labeled as such has steadily eroded since the Stonewall riots began the young gay porn modern American gay rights movement in 1969. 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 sees the female as a castrated male, seeing missing parts rather than a different anatomy. Transgender pornography features performers who cross-dress for sexual gratification, either for themselves or for their partners.