A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio. Since development and pronunciation of the buttocks begins at menarche mature milfs and declines with age, full buttocks are also a symbol of youth. In academic discourse, racial fetishism is a postcolonialist term found in the writings of authors such as Homi K. Creampie scenes depart from heterosexual pornographic convention in favor of a depiction that more closely mimics sexual intercourse as performed in ordinary life; they have been called the counterimage of facials. Examples of heterosexual hentai videos pornographic film series featuring creampies include Cream Filled Teens and Internal Cumbustion. Rape pornography features performers simulating rape. Watersports pornography features sexual activities involving urine, such as golden showers. 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. Group sex is sexual behavior involving more than two participants. The original definition of dogging – and which is still a closely related activity – is spying on couples having sex in a gay cock car or other public place. Foot fetish pornography features heavy emphasis on the feet of the participants, either in combination with kissing and genital sex or in the context of acts such as trampling or crush fetishism. Some techniques which may work for one individual can be difficult or uncomfortable for another. Many men who like trans partners of any variety, known as tranny chasers, do not necessarily identify as gay themselves. 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. Commercialized pornography accounts for a nearly US0 billion worldwide industry for the production of various media and associated products and services.