Body parts including fingers, tongue and penis may be used for anonymous oral, vaginal and/or anal intercourse. Especially popular gay boy porn in post-World War 2 Japanese culture. A variation on this is to place the fingers and thumb on the penis as if playing a flute, and then shuttle them back and forth. Clothed female, 3d hentai naked male is a genre of erotica featuring one or more nude men and one or more clothed women. Now facial cumshots are regularly portrayed in pornographic films, videos, magazines and internet web sites. In addition to mainstream pornography, the popularity of facials has led to creation of its own niche market, like video series that specialize in showing the act. 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. Bareback sex is physical sexual activity, especially sexual penetration, without the use of a condom. There is also some evidence that pornography can be used to treat voyeurism. Bobbi S. Examples include the Girls Gone Wild and Girls Who Like Girls Series. Group sex can occur between people of all sexual orientations and genders. In human sexuality, a threesome is sexual activity that involves three people at the same time. See big tit milf Gay-for-pay. Within a BDSM or D/s context, facesitting can be an especially intense form of erotic humiliation. When sexual activity is centered on one of the threesome, then the activity may be described as a gang bang of the person. Amateur porn has been called one of the most profitable and long-lasting genres of pornography. A pearl necklace is a slang term referring to a sexual act in which a man ejaculates semen on or near the neck, chest, or breast of another person. Since development and pronunciation of the buttocks begins at menarche and declines with age, full buttocks are also a symbol of youth. Insertion in pornography features women inserting various odd objects into their anus or vaginas.