In POV porn, the shooting style is generally similar to gonzo pornography, with the person receiving sexual gratification holding the camera him or herself—aiming it down at the actress or actor who is performing the sex act. The porn industry and viewing public were shocked by the then-taboo spectacle of a white woman having sex with a black man. Since mammary intercourse is a non-penetrative sex act, the risk of passing a sexually transmitted infection that requires direct contact between the mucous membranes and pre-ejaculate or semen is greatly reduced. Evolutionary psychologists suggest that rounded buttocks may have evolved to be desirable trait because they provide a visual indication of the woman gay cock youth and fertility. Portrayals of lesbians in the media suggest that society at large has been simultaneously intrigued and threatened porn milf by women who challenge feminine gender roles, and fascinated and appalled with women who are romantically involved with other women. The volume of semen that is ejaculated depends on several factors, including the male health, age, degree of sexual excitement, and the time since his last ejaculation. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, and their buttocks are objectified by porn as a result. Common phrases used to refer to these individuals are chicks with dicks or the derogatory term shemale, although these are generally considered pejorative among transwomen. Sexual orientation Pornography features an increasing variety of combinations of actors by their sexual orientation such as lesbian, gay, bisexual, and transsexuals hentai sex in addition to traditional heterosexual roles. Women with women Main article: Lesbianism in erotica: Lesbianism in contemporary pornography Lesbian or girl-girl pornography features women engaged in sex together, but is typically aimed at a male audience. It contains graphic sexual activity and visible penetration.