The fundamental hentai sex principles for the exercise of BDSM require that it should be performed with the informed consent of all involved parties. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions of interracial sexual activity. Erotic literature and pornographic films have been devoted to the sexual uses of glory holes. In the United States, creating, distributing, or possessing crush videos has been illegal since 1999, and many other countries also have banned them. While most tentacle erotica is animated, there are also a few live-action gay bear porn movies. Masturbation has been depicted in art since prehistoric times and is mentioned and discussed in very early writings. This is not due to a medical need. There are hentai porn pics currently no known laws forbidding the crushing of objects and insects, however the production or trade of crush erotica involving live vertebrates is condemned by animal rights activists and is illegal in many countries, including the United States and Great Britain. 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. As observation is encouraged, big tit milf voyeurism and exhibitionism are closely associated with dogging. High heel pornography involves women or men dressed in high heeled shoes. However the genre remains a very small proportion of the pornographic DVD market; for example at porn retailer HotMovies. When questioned about her particular kink Covét replied, If we women have to take it from behind, then why not a man? Gonzo porn is influenced by amateur pornography, and it tends to use far fewer full-body/wide shots in favor of more close-ups . It is also often mixed with other fetishes in practice, such as voyeurism, denial, etc. Facesitting is common among dominant and submissive individuals, for demonstrating superiority and for sexual gratification.