For some people, non-penetrative sex is the primary sexual activity of choice above all others. Some are aroused from wetting their diapers, others like messing their diapers. The primary subjects of pornographic depictions are pornographic models, who pose for still photographs, and pornographic actors or porn stars, who perform in pornographic films. Preggo pornography features pregnant performers and may include erotic lactation gaysex as lesbian hentai a fetish. Behind the Green Door was one of the first pornographic films to feature sex between a white actress with a black actor . At the end of the evening the female partners would randomly select keys from the bowl and leave with that key owner. This is commonly called double vaginal penetration or double stuffing. Mutual masturbation, mutual manual stimulation of the genitals between partners, can be a substitute for sexual penetration. Gonzo pornography is a style of pornographic film that attempts to place the viewer directly into the scene. Internationally, hentai is a catch-all term to describe a genre of anime and manga pornography. Some prefer a particular type of clothing to urinate. Standing up, a chair, the corner of an item of furniture, or even a washing machine can be used to stimulate the clitoris through the labia and clothing. The slave is usually strictly forbidden from placing their lips directly on the body of the dominant so the practice routinely involves them receiving much of the spray all over their face, hair and body, however, another way of doing this that applies mostly to male dominants, is to place the mouth on the head of the penis and drink the urine as it is released. Mutual masturbation foreplay The manual stimulation of each other genitals where the session porn milf eventually leads to sexual intercourse. Examples of mentally oriented practices are education games, during which the dominant requires certain forms of behavior from the submissive. Cartoon pornography is the portrayal of illustrated or animated fictional characters in erotic or sexual situations.