Initially, few animation studios in the United States attempted to produce animation for adult audiences, but later examples of animation produced for adults would gain mainstream attention and success. 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. It is sometimes described lesbian hentai as a sexual fantasy, by women or men, depicting an exhibitionist or physique worship scenario. Insertion in pornography features women inserting various gay fuck odd objects into their anus or vaginas. When sexual activity is centered on one of the threesome, then the activity may be described as a gang bang of the person. 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. Often a dominant woman, she may be called a Dom, Domme /ˈdɒm/, Femdomme, Domina, or Dominatrix, depending on context or personal preference. Clothed female, naked male is a genre of erotica featuring one or more nude men and one or more clothed women. The term lesbian is also used with regard to sexual identity or sexual behavior, regardless of sexual orientation, or as an adjective to characterize or associate nouns with female homosexuality or same-sex attraction. Softcore pornography generally contains nudity or partial nudity in sexually suggestive situations, but without explicit sexual activity, sexual penetration or extreme fetishism, while hardcore pornography may contain graphic sexual activity and visible penetration, including unsimulated sex scenes. The first pegging scene appears to have been in the non-pornographic mature milfs 1970 film Myra Breckinridge, based on the novel of the same name by Gore Vidal, although it was not explicit. Bareback sex is physical sexual activity, especially sexual penetration, without the use of a condom. While bondage is a very popular variation within the larger field of BDSM, it is nevertheless sometimes differentiated from the rest of this field.