Anti-pornography psychologist Ana Bridges and colleagues conducted a content analysis of best-selling heterosexual pornographic videos showing that over 96% of all scenes concluded with a male performer ejaculating onto the body of his female partner. Scenes of multiple penetration are common in pornography. Seconds after being deposited onto the face, the semen thickens, before liquefying 15–30 minutes later. Fetish cuckolding can have a wide range of expression, from pillow-talk fantasy between monogamous partners to extreme alternative lifestyles, depending on the couple. Simultaneous penetration of videos gays the vagina by two penises or other objects. Foot fetishism, foot partialism, foot worship, or podophilia is a pronounced sexual interest in feet. High heel pornography involves women or men dressed in high heeled shoes. Yiff or Yiffy pornography features Furry or anthropomorphic hentai videos animals in an erotic or sexual context. Bukkake videos are a relatively prevalent niche in contemporary pornographic films. Rough sex pornography is similar to pornography featuring sadomasochism, milf fuck and typically features a Top who humiliates and/or degrades a Bottom while being physically violent towards them. Social attitudes towards the discussion and presentation of sexuality has become more tolerant and legal definitions of obscenity have become more limited, leading to an industry for the production and consumption of pornography in the latter half of the 20th century. Gaping in pornography refers to scenes of anal sex with a focus on the recipient’s anus remaining open for a period of time after the erect penis or dildo is removed. Also see POV. Squirt pornography involves women ejaculating. Clothed female, naked male is a genre of erotica featuring one or more nude men and one or more clothed women. Sub-genres of Japanese porn Among the various sub-genres of Japanese pornography are the following: Lolicon ロリコン: This genre involves prepubescent and adolescent girls between the aged of 6-12.