Content featuring male bisexuality has been a growing trend since the advent of internet pornography. Starting with erotic stories and woodblock prints from before the 20th century, Japanese pornography hentai movies 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 . Dwarfs or midget pornography features performers who are dwarfs/midgets. Some may keep their hand stationary while pumping into it with pelvic thrusts in order to simulate the motions of sexual intercourse. Commercialized pornography accounts for a nearly US0 billion worldwide industry for the production of various media and associated products and services. Although interracial pornography theoretically can apply to depictions of sexual activity between performers of any different racial groups, the term is most commonly used for heterosexual sex acts between black and white performers. 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. Diaper fetishism is totally independent from pedophilia as the wearer derives pleasure only from the diaper and/or use of it. Clothes wetting: The person is sexually aroused by wetting one clothing or observing another person doing so. Once insertion is complete, the fingers are either clenched into a fist momporn or kept straight. Threesome can also refer to a love triangle, a three-way videos gays romantic relationship. These scenes may involve the female actor calling for the shot to be directed at some specific part of her body. However, bisexual pornography is often placed near the gay section in adult video stores, since many consumers are gay men. Films with risqué content commenced to be produced soon after the invention of the motion picture in the 1880s.