In more vigorous forms of fisting, such as punching or punchfisting, a fully clenched fist may be inserted and withdrawn slowly. As a result, little in history was documented to give an accurate description of how female homosexuality is expressed. The naked milf term sadomasochism is derived from the words sadism and masochism . It has also been recommended as a form of foreplay or safer sex. Comic books often featured characters being tied up and tying others up, particularly in damsel in distress plots. 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. Omorashi: The act of holding one own urine until the need to urinate is urgent, making another hold in their urine, or watching another person with an urgent need to urinate. Pornography may be presented in a variety videos gays of media, including books, magazines, postcards, photographs, sculpture, drawing, painting, animation, sound recording, film, video, and video games. Advocates of RACK argue that SSC can hamper discussion of risk because no activity is truly safe, and that discussion of even low-risk possibilities is necessary for truly informed consent. Dwarfs or midget pornography features performers who are dwarfs/midgets. Some women who engage in same-sex sexual activity may reject not only identifying as lesbians but as bisexual as well, while other women self-identification as lesbian may not align with their sexual orientation or sexual behavior; sexual identity is not necessarily the same as one sexual orientation or sexual behavior, due to various reasons, such as the fear of identifying their sexual orientation in a homophobic setting. Kinbaku means tight binding Kinbaku-bi which literally means the beauty of tight binding. It is commonly depicted in pornography, but very rarely in mainstream cinema. It is sometimes hentai sex combined with BDSM features. Each participant may engage in any type of sex acts with one or both of the others, such as vaginal, anal or oral sex or mutual masturbation.