Starting with erotic stories and woodblock prints from before the 20th century, Japanese pornography evolved into distinct subcategories with the media that in addition of pornographic videos and magazines featuring live actors, there is exist categories of pornographic manga , pornographic computer games , and pornographic anime . It concludes these findings suggest that an explanation for fat admiration may be that FAs are rejecting sociocultural norms of attractiveness. There may be more than two participants; both group sex and gang banging can be included. Group sex is sexual behavior involving more than two participants. Each participant may engage in any type of sex acts with one or both of the others, such as vaginal, anal or oral sex or mutual masturbation. Because the viewing of such films carried a social stigma, they were viewed at brothels, adult movie theaters, stag parties, at home, in private clubs and also at night cinemas. Lesbian pornography made for women is usually made by women, and usually features women who identify as lesbian or bisexual. Bondage/BDSM Bondage pornography features performers tied up or constrained in various ways. Transsexual porn star Wendy Williams has stated that transsexual porn is classified as Straight Specialty. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. A pearl necklace is a slang term referring to a sexual act in which a man ejaculates semen on or near the neck, chest, or breast of another person. Since at least 1973, it anime hentai has also been used to refer to a sexually attractive young woman. It is sometimes combined with momsex BDSM features. Snuff pornography involves the actual death of any of the participants, consenting or otherwise, simulated hot gay sex death is not considered snuff. In some societies, the terms fox, plum, chick, or chicken are preferred. If this is done using penises and/or strap-on dildos, this is sometimes called the sandwich or BigMac.