Another variant of reality pornography consists of normal couples that are filmed by professionals, in which case the only obvious distinction anime hentai from amateur pornography is the higher quality of production, filming and editing. Babysitter pornography features usually teenage girls being exploited and having taboo sex with older, male employers. Using the term shemale for a transsexual woman often implies that she is working in the sex trade. To tea bag is a slang term for the sexual act of a man placing his scrotum in the mouth of a willing sexual partner for pleasure or onto the face or head of another person. The anus has a relatively high concentration of nerve endings and can be an erogenous zone, and the receiver may receive pleasure from external anal stimulation. Hentai is gay twinks the various forms of Japanese milf xxx pornography, including H-manga, H-anime, and H-computer games. Sometimes special furniture is used, such as a queening stool or smotherbox. The 1979 U. Spanking or whipping pornography involves spanking or whipping, generally of the buttocks, with the hand or with other objects such as belts, switches, paddles, brushes, or whips. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions of interracial sexual activity. Watersports pornography features sexual activities involving urine, such as golden showers. Male masturbation may differ between males who have been circumcised and those who have not. A female dominant in a master/slave relationship is often termed a Mistress, not to be confused with the colloquial usage of mistress as a kept sexual partner without a similarly formalized power relationship. The stimulation may involve hands, fingers, everyday objects, sex toys or combinations of these. The speed of the hand motion will vary from person to person, although it is not uncommon for the speed to increase as ejaculation nears and for it to decrease during the ejaculation itself. Technically this is a form of exhibitionism rather than group sex per se.