Bisexual DVDs sell much better online than in adult video stores, possibly gay boy porn due to customers in stores feeling embarrassed to buy them. Said that the female buttocks evolved in the context of females competing for the attention and parental commitment of powerful resource-controlling males as an honest display of fat reserves that could not be confused with another type of tissue, although T. Sexologist Alfred Kind suggested that the buttocks is the primary sexual presentation site in primates. Often, strong views are expressed with regard to anal sex; it is controversial in various cultures, especially with regard to religion, commonly due to prohibitions against anal sex among gay men or teachings about the procreative purpose of sexual activity. In modern BDSM vernacular, the queening stool allows open access to the crotch while seated. These scenes may either have the cameraman directly engaging in sex or merely filming others having sex. Shibari is a Japanese word that literally anime hentai means to tie or to bind. These scenes may involve the female actor calling for the shot to be directed at some specific part of her body. While bondage is a very popular variation within the larger field of BDSM, it is nevertheless sometimes differentiated from the rest of this field. There is no singular or archetypical behavior; therefore, a wide range of thought patterns and behaviors exist, but all tends to be a harmless and efficacious release from some kind of pressure. Hugo Ohira, director of marketing for Silvercash, rhetorically asks Who does not like spewing their load on a pretty young face? Usually that person prefers to stage the wetting so that his/her legs become soaked with naked milf urine. The term applies to the depiction of the act rather than the act itself, and so does not include live exhibitions like sex shows and striptease. Although interracial pornography theoretically can apply to depictions of sexual activity between performers of any different racial groups, the term is most commonly used for heterosexual sex acts between black and white performers.