New York photographer Irving Klaw also published illustrated adventure/bondage serials by fetish artists Eric Stanton, Gene Bilbrew, Adolfo Ruiz and others. Irrespective of the legal or social view of pornography, it has been used in a number of contexts. Bukkake pornography involves a performer, usually female, onto whom several men or women ejaculate, usually on the face. Additionally, the buttocks give an indication of the shape and size of the pelvis, which impacts reproductive capability. Voyeur pornography may also include shots of topless women on topless beaches who are unaware of the cameras but may legally be photographed due to the public setting. Sadism describes sexual pleasure derived by inflicting pain, degradation, humiliation on another person or causing another person to suffer. In humans, females generally have more round and voluptuous buttocks, caused by estrogen that encourages the body to store fat in the buttocks, hips, and thighs. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. Real school shots or videos which are sexualized may violate privacy laws in some countries. Some pornographic films use an artificial semen substitute to simulate or enhance creampie shots. It is geared towards heterosexual men, who gaysex most horny milfs typically define a threesome as such. The first explicit pegging scene is believed to have been in the 1975 pornographic film The Opening of Misty Beethoven. A scene where many women have sex with one man is referred to as a reverse gang-bang. There are number of types of sex parties: Swinger party/gathering A swinger party or partner-swapping party is a gathering at which individuals or couples in a committed relationship can engage in sexual activities with others as a recreational or lesbian hentai social activity. Bestiality is illegal in many countries. Coprophilia , also called scatophilia or scat , is the paraphilia involving sexual arousal and pleasure from feces.