Bukkake, Gokkun, Omorashi, and tentacle erotica are few uniquely Japanese genres known hentai videos to western viewers. Com, there are only 655 bisexual titles out of a catalogue of more than 90,000 films. Others may also use vibrators and other sexual devices more commonly associated with female masturbation. In some areas, there are laws stating it is not legally possible to consent to be killed, and elsewhere it may still be legally dubious . The fundamental principles for the exercise of BDSM require that it should be performed with the informed consent of all involved parties. However the genre remains a very small proportion of the pornographic DVD market; for example at porn retailer HotMovies. Voyeur or peeping Tom pornography is usually more staged with the subjects aware of the cameras, sometimes openly including this exhibitionist awareness. Rough sex pornography is similar to pornography featuring sadomasochism, and typically features a Top who humiliates and/or degrades a Bottom while being physically gay boy porn violent towards them. Enema pornography involves adults given enemas to others, often fake. Social attitudes towards the discussion and presentation of sexuality has become more tolerant and legal definitions of obscenity have become more limited, leading to an industry for the production and consumption of pornography in the latter half of the 20th century. It has been described as professionally made porn which seeks to emulate the style of amateur pornography. Boot fetishism is a sexual fetish dedicated to boots. Bestiality momporn pornography involves the sexual attraction of humans to animals. A sexual fetish may be regarded as an enhancing element to a romantic/sexual relationship achieved in ordinary ways or as a mental disorder/disorder of sexual preference if it causes significant psychosocial distress for the person or has detrimental effects on important areas of their life. Japanese rope bondage is distinguished by its use of specific katas and aesthetic rules. Jail/Prison/Police pornography involves people in police custody or inmates in jails or prisons in various sexual situations, such as strip searches or body cavity searches.