Commenting on why there are not as many female macrophiles, psychologist Helen Friedman theorized that because women in most societies already view men as dominant and powerful, there no need for them to fantasize about it. This type of pornography is almost exclusively hentai, as true hermaphroditic humans are not fertile and are not usually found in nature. When used as an alternative to penile-vaginal penetration, the goal may be to preserve virginity or to prevent pregnancy. The term comes from the French voyeur, one who looks. The loose 3d hentai and direct camera work often includes tight shots of the genitalia, unlike some traditional porn. There is, however, no third party camera work involved. 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. If dramatic skills are not involved, a performer in a porn film may also be called a model. They may regard it as an enhancing element of their momsex sex lives or as their primary form of sexual activity. HIV is among the infections that gay twink porn require such direct contact and is therefore very unlikely to be transmitted via mammary intercourse. The use of the word creampie to describe such scenes originated in U. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans. The phrase buttered bun is sometimes used to refer to the owner of the orifice in question. Sub-genres can also be classified into the characteristics of the performers or the type of sexual activity on which it concentrates, and not necessarily on the market to which each sub-genre appeals. Felching is a sexual practice involving the act of orally sucking semen out of the vagina or anus of one partner. The term sadomasochism is derived from the words sadism and masochism . It is geared towards heterosexual men, who most typically define a threesome as such.