Lesbian pornography made for women is usually made by women, and usually features women who identify as lesbian or bisexual. Going back at least as far as the Christy twins in the 1970s, depictions of incest and particularly incest between twins has been a feature of gay pornography. A variation on this is to place the fingers and thumb on the penis as if playing a flute, and then shuttle them back and forth. For legal reasons, the vast majority of so-called reality porn involves professional lesbian milfs actors and actresses pos celebrity sex videos ing as so-called amateurs. In addition to mainstream pornography, the popularity of facials has led to creation of its own niche market, like video series that specialize in showing the act. Pornographic films present sexual fantasies and usually include erotically stimulating material such as nudity. The smotherbox is placed on a stable surface. Targets young gay porn the male audience, celeb gossip but is hentai sex much less popular than Yaoi. Since the 1980s, many practitioners and organizations have adopted the motto safe, sane and consensual, commonly abbreviated as SSC, 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. A female dominant in a master/slave relationship is often termed a Mistress, not to be confused with the colloquial usage of mistress as a kept sexual partner without a similarly formalized power relationship. Lucky Pierre is slang for a person performing both receptive and insertive anal and/or vaginal sex simultaneously during a threesome, being positioned between the two partners. 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. Although pornography has usually focused on heterosexuality, due to the adult anime prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory.