Preggo pornography features pregnant performers and may include erotic lactation as a fetish. The name was coined from the title of the controversial book. There has been an increase in discussion and portrayal of masturbation in art, popular music, television, films, and literature. Multiple men and women Bisexual pornography features one woman and two men who all perform sex acts on each other. Though there have been numerous gang bang pornographic films since the 1980s, they usually involved no more than half a dozen to a dozen men. Sigmund Freud considered foot binding as a form of fetishism. Some anthropologists and sociobiologists believe that breast fetishism derives from the breasts similarity to buttocks, but instead provide sexual attraction from the front of the body. These styles milf xxx are much closer to the style of bondage scenes in mainstream television. If one person is penetrated by two objects, it is generically called double penetration . The term hentai porn combines elements of the Freudian psychoanalytic fetish and the Marxist commodity fetish, and is used in the context of British, Spanish and French colonialism and imperialism and their aftereffects. Double Stuffed , Double Vaginal , or Double Anal pornography involves the penetration of one orifice by two penises or other objects. The queening stool is also related to a smotherbox, which also allows the person under the seat to be locked in place, restrained by the neck as in a set of stocks. A scene where many women have sex with one man is referred to as a reverse gang-bang. Sexual relations between women have been illustrated as well as narrated, but much of the written material from the early modern period has been destroyed. Double penetration of the vagina, anus and mouth, can involve: Simultaneous penetration of the anus by two penises or other objects. The niche popularity grew significantly in the latter half of the first decade of the 2000s. It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is gaysex 18.