It may involve sexual attraction to women who are pregnant or appear pregnant, attraction to lactation, or attraction to particular stages of pregnancy such as impregnation or childbirth. The higher pay scale and profile within a production often leads to group scenes where a straight actor only tops. The nipples are erogenous zones, and vigorous stimulation of them during masturbation usually causes the penis to become erect more quickly than it would otherwise. Pornographic films are generally classified into sub-genres which describe the sexual fantasy which the film and actors attempt to create. Interracial pornography typically employs ethnic and racial stereotypes in its depiction of performers and many of interracial pornographic films still include racial stereotypes, although the segregation of actors by race has diminished considerably. Currently, animated television series aimed at adults are some of the most popular gay hentai and critically acclaimed forms of entertainment. This category gay cock also includes momsex pornographic home movies. Reality Reality pornography refers to real or faked amateur encounters. In recent years, Japanese films of this genre have become more common in the USA and Europe although it still remains a small, fetish-oriented part of the adult film industry. Women in homosexual relationships responded to this designation either by hiding their personal lives or accepting the label of outcast and creating a subculture and identity that developed in Europe and the United States. In September 2003 the BBC reported on the new dogging craze. Partners can engage in penetrative sex, known as full swap, or choose to soft swap in which they engage only in non-penetrative sex. It can be combined with fellatio and the woman may move her breasts up and down on the penis for an additional stimulation, usually before the man reaches orgasm. Transsexual pornography features transwomen performers, who typically have male genitalia and augmented female breasts . Sloppy seconds is a slang phrase for when a man has sexual intercourse with another person who already has received another man penis in the relevant orifice and is therefore wet or sloppy.