Other objects such as ball point pens and thermometers are sometimes used, although this practice can lead to injury and/or infection. Older names for a pornographic film include stag film, and blue movie. As of 2013, little analysis of this paraphilia has been reported in medical literature. The phrase is commonly found on porn sites. Oral sex pornography frequently features a person performing fellatio, and less frequently cunnilingus. If dramatic skills hentai movies are not involved, a performer in a porn film may also be called a model. Some men also enjoy anal stimulation, with fingers or otherwise, without any prostate stimulation. Several hundred exclusively pegging films were produced, as well as twice as many bisexual and straight films with strap-on scenes. The original definition of dogging – and which is still a closely related activity – is spying on couples having sex in a car or other public place. There may be more than two participants; both group sex and gang banging can be included. Women porn is often produced by women and aimed specifically at the female market - rejecting the view that men are turned on by porn but women only by a box of chocolates. Is also common of the furry genre. Generally, interest differs between people, and gender depends on sexual orientation. The genres of pornography are based on the type of activity featured and the category of participants, for example porn milf mateur pornography is a category of pornography that features models, actors or non-professionals performing without pay, or actors for whom this material is their only paid modeling work. Because the viewing of such films carried a social stigma, they were viewed at brothels, adult movie theaters, stag parties, at home, in private clubs and also at night cinemas. Originating in Japan in the 1980s, the genre subsequently spread to North America and Europe, and crossed over into gay pornography. A male voyeur is commonly labeled Peeping Tom, a term which originates from the Lady Godiva legend.