It is typically animated pornography, as the legal age to be featured in gay movies a pornographic film in Japan is 18. Bestiality is illegal in many countries. Individuals are also sometimes abbreviated when referred to in writing, so a dominant person may be referred to as a Dom for a man, and a Domme for a woman. Typically featured are hitting, choking, name-calling and hair-pulling. The genres of pornography are based on the type of activity featured and the category of participants, for example mateur pornography is a category of pornography that features models, actors or non-professionals performing without pay, or actors for whom this material is their only paid modeling work. The industry porn milf generally refers to such films as adult films, which is part of adult entertainment. This may help them develop their orgasm, increase its pleasure, and may inspire them to masturbate on a more frequent basis. Group sex most commonly takes place in a private sex party or semi-public swinger gathering, but may also take place at massage parlors or brothels or, in some jurisdictions, at purpose-built locations such as sex clubs. The smotherbox is placed on a stable surface. Jerk off instruction features a performer encouraging or instructing the viewer to masturbate, often culminating in a countdown at the end of which the viewer is invited to induce orgasm. Both sexes sometimes apply lubricating substances to intensify sensation. The object or situation of interest is called the fetish; the hentai sex person who has a fetish for that object/situation is a fetishist. Starting with erotic stories and woodblock prints from before the 20th century, Japanese pornography evolved into distinct subcategories with the media that in addition of pornographic videos and magazines featuring live actors, there is exist categories of pornographic manga , pornographic computer games , and pornographic anime . There has been an increase in discussion and portrayal of masturbation in art, popular music, television, films, and literature.