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. The inside of a smotherbox is often padded to provide support for gay bear porn their neck and prevent their head from moving. Internal ejaculations, followed by images of semen dripping from the anus, are sometimes depicted in bareback gay pornography, lesbian hentai where they are referred to by the term breeding or the reverse money shot. Currently, animated television series aimed at adults are some of the most popular and critically acclaimed forms of entertainment. A facial is a form of non-penetrative sex, though it is generally performed after some other means of sexual stimulation, such as vaginal sex, anal sex, oral sex or masturbation. For legal reasons, the vast majority of so-called reality porn involves professional actors and actresses posing as so-called amateurs. This technique may include the use of a simulacrum, or artificial vagina. The stigma of being gay or labeled as such has steadily eroded since the Stonewall riots began the modern American gay rights movement in 1969. Several hundred exclusively pegging films were produced, as well as twice as many bisexual and straight films with strap-on scenes. Since the 1980s, many practitioners and organizations have adopted the motto safe, sane and consensual, commonly abbreviated as SSC, naked milf which means that everything is based on safe activities, that all participants be of sufficiently sound/sane mind to consent, and that all participants do consent. Gloryhole pornography features women performing fellatio on unidentified men through a small hole made in a bathroom divider. Group sex is sexual behavior involving more than two participants. Celebrity sex tapes are amateur or professionally-made recordings of sex acts, as performed by a celebrity and their partner. Depictions of male and female masturbation are common in pornography, including gay pornography.