Regardless of its origin, BDSM is used as a catch-all phrase to include a wide range of activities, forms of interpersonal relationships, and distinct subcultures. Incest pornography is a genre of pornography involving the depiction of incest . The Japanese sex industry gay boy porn uses the term Paizuri . Arguably gay hentai the most famous example of the genre is the Taboo series. Moreover, many gay or bisexual men who star in gay porn films may wish to be identified publicly as heterosexual for personal or professional reasons. Cum swapping pornography involves performers trading semen between their mouths. Most consumers of bisexual pornography do not identify as gay. To tea bag is a slang term for the sexual act of a man placing his scrotum in the mouth of a willing sexual partner for pleasure or onto the face or head of another person. In the United States, creating, distributing, or possessing crush videos has been illegal since 1999, and many other countries also have banned them. Smoking fetish involves performers smoking cigarettes, cigars, joints, and/or blunts. 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. BDSM pornography depicts bondage and discipline, domination and submission, sadism and masochism. In a bath or shower a female may direct tap water at her clitoris and vulva. This yields a view that would not be obtainable directly through the eyes of a person while momsex experiencing the sex act. Bodily functions Menstrual or red rhapsody pornography features sexual activities involving women who are menstruating, with a focus on the menstrual blood. Caro rejected that as being a necessary conclusion, stating that female fatty deposits on the hips improve individual fitness of the female, regardless of sexual selection. Buck Angel is the best-known actor in this genre. Seconds after being deposited onto the face, the semen thickens, before liquefying 15–30 minutes later.