Real school shots or videos which are sexualized may violate privacy laws in some mature milfs countries. Cartoon pornography depicts illustrated or animated fictional characters in erotic and sexual hentai porn situations. To avoid soreness from this resulting friction, some may prefer to use a personal lubricant, masturbation cream or gay movies saliva during masturbation. Positions can also be chosen specifically for added effects such as increased humiliation, elevation and suspension. Diaper fetishism is totally independent from pedophilia as the wearer derives pleasure only from the diaper and/or use of it. The term BDSM dates back to 1969; however, the origin of the term BDSM is unclear and is believed to have been formed either from joining the term B&D with S&M , or as a compound initialism from B&D, D&S , and S&M. Bondage pornography specializes in the depiction of sexual bondage or BDSM activities as photographs, stories, movies, or drawings. A study of 164 males in Finland from two SM clubs found that 18.2% had engaged in coprophilia; 3% as a sadist, 6.1% as a masochist, and 9.1% as both. 18% of heterosexuals and 17% of homosexuals in the study pool had tried coprophilia, showing no statistically significant difference between heterosexuals and homosexuals. Rimjob pornography centers around anilingus. Being forced to wear diapers as a form of humiliation is sometimes a behavior encountered in sexual masochism. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. Reality and voyeur pornography, animated videos, and legally prohibited acts also influence the classification of pornography. Most bisexual porn is made by small production companies rather than the major studios. Reality pornography is a genre of pornography where staged scenes, usually shot in cinéma vérité fashion, set up and precede sexual encounters. Gay pornography is the representation of sexual activity between males. Lying face down one may use the hands, one may straddle a pillow, the corner or edge of the bed, a partner leg or some scrunched-up clothing and hump the vulva and clitoris against it.