Works in this genre may explore philosophical, political or social issues. However, gay pornography in the modern world is mostly concentrated in the making of home videos , cable broadcast and emerging video on demand and wireless markets, as well as images and movies for viewing on the Internet. HIV is among the infections that require such direct contact and is therefore very unlikely to be transmitted via mammary intercourse. Some people masturbate by using machines that simulate intercourse. These horny milfs are often fake. Individual tastes and preferences in the area of sexuality may overlap among these areas, which are discussed separately here. As well as traditional attraction, the topic also incorporates feederism and gaining, where sexual gratification is obtained via the process of gaining body fat. Being forced to wear diapers as a form of humiliation is sometimes a behavior hentai sex encountered in sexual masochism. Lolita pornography caters to ephebophiles. Point of view pornography is adult entertainment filmed to look as if the watcher were experiencing the sex act themselves. Lolita pornography that features actual teenage girls under the age of 18 is illegal in most countries and treated as child or youth pornography. The introduction of the home video and Internet saw a boom in the worldwide porn industry that generates billions of dollars annually. By comparison, gonzo pornography puts the camera right into the action, often with gay fuck one or more of the participants both filming and performing sexual acts, without the usual separation between camera and performers seen in conventional porn and cinema. Behind the Green Door was one of the first pornographic films to feature sex between a white actress with a black actor . His most famous model was Bettie Page, who became the first celebrity of bondage film and photography. The genre is popular enough in Japan that it is even the subject of parody. Coprophilia , also called scatophilia or scat , is the paraphilia involving sexual arousal and pleasure from feces.