Going back at least as far as the Christy twins in the 1970s, depictions of incest and particularly incest between twins has been a feature of gay pornography. English adopts and uses hentai as a genre of pornography by the commercial sale and marketing of explicit works under this label. There is also some evidence that pornography can be used to treat voyeurism. Watersports pornography features sexual activities involving urine, such as golden showers. The person sat upon may be in bondage, sexually submissive, or simply held down by the body-weight of the other person. Babysitter pornography features usually teenage girls being exploited and having taboo sex with older, male employers. 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. An orgy is a gathering where guests freely engage in open and unrestrained sexual activity or group sex; and a bunga bunga orgy is an orgy in which participants have sex underwater, such as in a swimming pool or a hot tub. A sub-set of vaginal fisting attempts to photograph the female cervix immediately after the fist is removed from the now-gaping vagina. Targets the male audience, but 3d hentai is much momporn less popular than Yaoi. Hentai is the various forms of Japanese pornography, including H-manga, H-anime, and H-computer games. Mutual masturbation can be practiced by males or females in pairs or groups with or without actually touching another person as indicated by the following examples of contact versus non-contact scenarios: Non-contact mutual masturbation Two people masturbating in the presence of each other but not touching. Performers are usually clean-shaven, thinner and more effeminate than ones in mainstream gay pornography. Twink pornography features younger performers, and usually features young men under 30 who identify as gay or bisexual. In some societies, the terms hot gay sex fox, plum, chick, or chicken are preferred.