Mammary intercourse is known as titty-fucking, titfuck, or a titjob in the United States, as well as tit wank or French fuck in the United Kingdom - the latter term dating back to the 1930s; while a more jocular equivalent is a trip down mammary lane. Is also common of the furry genre. The momporn term is typically used by the cinematographer within the narrative framework of a pornographic film, and since the 1970s has become a leitmotif of the hardcore genre. Spanking can be administered in a number of spanking positions. Buttocks are sometimes emphasized in pornography, where they are often referred to as booty. This is commonly called double vaginal penetration or double stuffing. The full-weight body-pressure, moisture, sex odors and darkness can be perceived as powerful sexual gay bear porn attractions or compulsions. The glans itself may widen and lengthen as the stimulation continues, becoming slightly darker in colour, while the gliding action of the foreskin reduces friction. Clothed male, naked female is one-sided female nudity in which one or more females are nude while one or more men are clothed. A bisexual threesome may involve a man having sex with a man and a woman, the woman having sex with a man and a woman, or all three having sex with each other. Some pornographic films use an artificial semen substitute to simulate or enhance creampie shots. For instance, Amateur Allure has a trademark shot where the sexually performing cameraman circles a handycam around the sexually performing model head. A related term used in the genre is the term cougar, which implies an older woman as predator. They may be noted for using risqué themes, graphic violence, sexuality or black comedy in hentai porn a manner that is unsuitable for younger audiences. Its gain in prominence has been attributed to its depiction in the film Pecker, which was released in 1998. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans.