The genres of pornography are based on the type of activity featured and the category of participants, for example 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. Other objects such as ball point pens and thermometers are sometimes used, although this practice can lead to injury and/or infection. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans. Normal quantities of ejaculate range from 1.5 to 5.0 milliliters . Diaper pornography involves performers wearing diapers, sometimes with an adult performer acting in the role of a caretaker. The strategies and tactics that are used videos porno gay to smuggle one of the couple into and naked milf out of the toilet undetected are as important or almost as important as the urination. A sub-set of vaginal fisting attempts to photograph the female cervix immediately after the fist is removed from the now-gaping vagina. Originating in Japan in the 1980s, the genre subsequently spread to North America and Europe, and crossed over into gay pornography. Depictions of male and female masturbation gay hentai are common in pornography, including gay pornography. A crush fetish is a fetish in which one is sexually aroused usually when someone crushes objects, food, and sometimes small animals with their body, usually under their foot, or when crushed oneself. The other person may do the same during or after. The name is a reference to gonzo journalism, in which the reporter is part of the event taking place. Creampie scenes depart from heterosexual pornographic convention in favor of a depiction that more closely mimics sexual intercourse as performed in ordinary life; they have been called the counterimage of facials. The concept of lesbian, to differentiate women with a shared sexual orientation, is a 20th-century construct. Pegging is a sexual practice in which a woman performs anal sex on a man by penetrating the man anus with a strap-on dildo.