Sexual orientation Pornography features an increasing variety of combinations of actors by their sexual orientation such as lesbian, gay, bisexual, and transsexuals in addition to traditional heterosexual roles. Femdom features BDSM scenes in which the dominant partner is female. On May 27, 2010 the television program The Doctors discussed the topic with dozens of teens, parents, and professionals. The existence of such content in commercially naked milf available pornography is widely considered an urban legend. On the other hand, the masochist enjoys being hurt, gay boy porn humiliated, or suffering within the consensual scenario. The act may be carried out face to face, or head to tail, with the woman recommended to be on top if she has smaller breasts. For some people, non-penetrative sex is the primary sexual activity of choice above all others. Foot fetish pornography features heavy emphasis on the feet of the participants, either in combination with kissing and genital sex or in the context of acts such as trampling or crush fetishism. Real medical shots or videos may violate privacy laws in some countries. The concept of lesbian, to differentiate women with a shared sexual orientation, is a 20th-century construct. Evolutionary psychologists suggest that rounded buttocks may have evolved to be desirable trait because they provide a visual indication of the woman youth and fertility. Voyeur pornography may also include shots of topless women on topless beaches who are unaware of the cameras but may legally be photographed due to the public setting. The first explicit pegging scene is believed to have been in the 1975 pornographic film The Opening of Misty Beethoven. The definition clash also appears with the English definition of yuri as any lesbian relationship, as opposed to its sexually explicit definition in Japan. The porn industry and viewing public were shocked by the then-taboo spectacle of a white woman having sex with a black man. Group sex pornography features at least two men and lesbian hentai two women , usually more, who all perform sex acts on each other.