Often, strong views are expressed with regard to anal sex; it is controversial in various cultures, especially with regard to religion, commonly due to prohibitions against anal sex among gay men or teachings about the procreative purpose of sexual activity. The phrase is commonly found on porn sites. A common way that these are depicted in a single scene is with one woman and two men performing together. Interracial pornographic films naked milf have experienced an explosion in popularity, becoming one of the fastest-growing and biggest-selling genres. Actual upskirt or downblouse shots may violate privacy laws in some countries. First found in softcore movies and erotic thrillers, depictions of lesbianism entered mainstream cinema in the 1980s. Especially popular in post-World War 2 Japanese culture. Bisexual pornography is a genre of pornography which most typically depicts one woman and two men who all perform hentai porn sex acts on each other. Comic books often featured characters being tied up and tying others up, particularly in damsel in distress plots. When sexual activity is centered on one of the threesome, then the activity may be described as a gang bang of the person. Simultaneous penetration of the mouth and either the vagina or anus. Entacle erotica describes a type of pornography most commonly found in Japan which integrates traditional pornography with elements of bestiality and a fantasy, horror, or science-fiction theme. Other possibilities are possible, such as a man having sex with two women who are having sex with each other. Guro or Gore is a genre of Japanese pornography involving blood, gore, disfiguration, violence, mutilation, urine, enemas, or feces. For legal reasons, the vast majority of so-called reality porn involves professional actors and actresses posing as so-called amateurs. Rough sex pornography is similar to pornography featuring sadomasochism, and typically features a Top who humiliates and/or degrades a Bottom while being physically gay twink porn violent towards them.