Examples include the Girls Gone Wild and Girls Who Like Girls Series. In addition to mainstream pornography, the popularity of facials has led to creation of its own niche market, like video series that specialize in showing the act. This fetish sometimes originates from childhood memories of needing, or of seeing another needing, to urinate. Real enema shots or videos of true medical situations may violate privacy laws in some countries. Shemale is a term primarily used in sex work to describe a trans woman with male genitalia combined with female secondary sex characteristics, usually including augmented female breasts, from breast augmentation and/or use of hormones. The reverse of this, in which nude women interact with clothed men, is called Clothed male, naked female . Facial cum shots are currently regularly portrayed in pornographic films and videos, often as a way to close a scene. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material gay hentai has a long history as well, which reaches back to Greek antiquity, if not to prehistory. Matsuo used amateur actresses in his videos, and he usually traveled to their hometowns for the filming. A sub-set mature milfs of vaginal fisting attempts to photograph the female cervix immediately after the fist is removed from the now-gaping vagina. In human sexuality, a threesome is sexual activity that involves three people at the same time. Another variant of reality pornography consists of normal couples that are filmed by professionals, in which case the only obvious distinction from amateur pornography is the higher quality of production, filming and editing. Starting with erotic stories and woodblock prints from before the 20th century, Japanese pornography evolved into distinct subcategories with the media that in addition of pornographic videos and gay cock magazines featuring live actors, there is exist categories of pornographic manga , pornographic computer games , and pornographic anime .