In pornography, depictions of lesbian sex form a popular subgenre, directed toward a male heterosexual and female homosexual audience. Sometimes special furniture is used, such as a queening stool or smotherbox. Babysitter pornography mature milfs features usually teenage girls being exploited and having taboo sex with older, male employers. The exact source and nature of the fluid continue to be a topic of debate among medical professionals, which is also related to doubts over the existence of the G-Spot. Making a pearl necklace is one of the activities that sex workers use as safe sex alternatives for people who refuse to wear condoms. Especially popular in post-World War 2 Japanese culture. Greater economic gay hentai and social freedom allowed them gradually to be able to determine how they could form relationships and families. Male masturbation may differ between males who have been circumcised and those who have not. Some couples use a threesome as a way to develop a love triangle . When all regions of the face are included, facial cum shots comprise approximately 62% of scenes where external ejaculation occurs. Also see POV. Others may also use vibrators and other sexual devices more commonly associated with female masturbation. One-sided male nudity can also arise when a male disrobes as part of a male striptease. Body parts including fingers, tongue and penis may be used for anonymous oral, vaginal and/or anal intercourse. The sub-genres usually conform to certain conventions, and each may appeal to a particular audience. Erotic spanking is the act of spanking another person for the sexual arousal or gratification of either or both parties. Mammary intercourse is said by Alex Comfort to produce mutual orgasm in women with sensitive breasts , and it was one of the nine substitute exercises for penetrative sexual activities, as detailed in gay fuck the Paradis Charnels of 1903. As with most forms of sexual activity, anal sex participants risk contracting sexually transmitted infections . Lesbian pornography made for women is usually made by women, and usually features women who identify as lesbian or bisexual.