The loose and direct camera work often includes tight shots of the genitalia, unlike some traditional porn. Works in this genre may be considered adult for any number of reasons. In Japan, point of view pornography is referred to as hamedori . Though there have been numerous gang bang pornographic films since gay movies the 1980s, they usually involved no more than half a dozen to a dozen men. Internationally, hentai is a catch-all term to describe a genre of anime and manga pornography. The term sadomasochism is derived from the words sadism and masochism . Additionally, the buttocks give an indication of the shape and size of the pelvis, which impacts reproductive capability. Those with diaper-related paraphilias differ widely in their focus of attention. The term pearl necklace is used by some because the drops of semen deposited by the man resemble a necklace of translucent white pearls. The other person may do the same during or after. The naked appearance of actress Demi Moore in the advanced stage of pregnancy on the cover horny milfs of Vanity Fair magazine in 1991 marked the beginning of a period which has since seen pregnancy presented by celebrities as a glamorous state of living, while also creating a market for photographers to produce images of pregnant mothers, and for fashion stylists to introduce pregnancy styling to their business. Studies have found that masturbation is frequent in humans of both sexes and all ages, although there is variation. In 1988, a sex tape caused significant damage to Rob Lowe career. In the West, masturbation in private or with a partner is generally considered a normal and healthy part of sexual enjoyment. 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 hentai movies in a committed relationship can engage in sexual activities with others as a recreational or social activity. Interactive pornography, available in CD-ROM and DVD format, allows the viewer to select the particular acts performed at any one time, sometimes with the camera providing a first person view.