In Japanese, the term describes any type of perverse or bizarre sexual desire or act; it does not represent a genre of work. Such grounds and even the definition of pornography have differed in various historical, cultural, and national contexts. Masturbation is the self-sexual stimulation of the genitals for sexual arousal or other sexual pleasure, usually to the point of orgasm. Reality pornography is a genre of pornography where staged scenes, usually shot in cinéma vérité fashion, set up and precede sexual encounters. Lying face down one may use the hands, one may straddle a pillow, the corner or edge of the bed, a partner leg or some scrunched-up clothing and hump the vulva and clitoris against it. Reality and voyeur pornography, animated videos, and legally prohibited acts also influence the classification of pornography. Hentai narrow Japanese usage and broad international usage are often incompatible. His most famous model was Bettie momsex Page, who became the first celebrity of bondage film and photography. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, and their buttocks are objectified by porn as a result. The loose and direct camera work often includes tight shots of the genitalia, unlike some traditional porn. Evolutionary psychologists suggest that rounded buttocks may have evolved hentai videos to be desirable trait because they provide a visual indication of the woman youth and fertility. The volume of semen that is ejaculated depends on several factors, including the male health, age, degree of sexual excitement, and the time since his last ejaculation. These actors often play the top roles but gay boy porn this is not always the case, such as with Kristen Bjorn and some Bel Ami models. Creampie, also known as internal cum shot, and, in homosexual contexts, also known as breeding and seeding, is a slang term used in pornography to describe when a male ejaculates inside his partner vagina or anus.