Pornographic films present sexual fantasies and usually include erotically stimulating material such as nudity. A common way that these are depicted in a single gay hentai scene is with one woman and two men performing together. Matsuo used amateur actresses in his videos, and he usually traveled to their hometowns for the filming. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. Softcore pornography generally contains nudity or partial nudity in sexually suggestive situations, but without explicit sexual activity, sexual penetration or extreme fetishism, while gay movies hardcore pornography may contain graphic sexual activity and visible penetration, including unsimulated sex scenes. It is sometimes described as a sexual fantasy, by women or men, depicting an exhibitionist or physique worship scenario. It is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual assault or domestic violence. The stigma of being gay or labeled as such has steadily eroded since the Stonewall riots began the modern American gay rights movement in 1969. Greater economic and social freedom allowed them gradually to be able to determine how they could form relationships and families. The 1979 U. 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. Participants usually derive pleasure from this, even though many of the practices—such as inflicting pain or humiliation or being restrained—would be unpleasant under other circumstances. Each participant may engage in any type of sex acts with one or both of the others, such as vaginal, anal or oral sex or big tit milf mutual masturbation. In September 2003 the BBC reported on the new dogging craze. 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.