The definition clash also appears with the English definition of yuri as any lesbian relationship, as opposed to its sexually explicit definition in Japan. Bareback sex is physical sexual activity, especially sexual penetration, without the use of a condom. Bisexual pornography is a genre of pornography which most typically depicts one woman and two men who all perform sex acts on each other. The rise of the Internet in the late 1990s and early 2000s similarly changed the way pornography film was distributed and furthermore complicated the censorship regimes around the world and the legal prosecution of obscenity. Saliva pornography involves salivation and saliva. Depictions of male and female masturbation are common in pornography, including gay pornography. In September 2003 the BBC reported on the new dogging craze. Squirt pornography involves women gay movies ejaculating. These scenes may either have the cameraman directly engaging in sex or merely filming others having sex. A female dominant in a master/slave relationship is often termed a Mistress, not to be confused with the colloquial usage of mistress as a kept sexual partner without a similarly formalized power relationship. The smotherbox is placed on a stable surface. By Japanese law, the genitals of actors and actresses must be censored and up the mid-1990 so was the depiction of pubic hair. A variant of A2M is ATOM where a performer inserts his penis directly from one recipient anus into a second recipient mouth. The term discipline describes psychological restraining, hentai movies with the use of rules and punishment to control overt behavior. Originating in Japan in the 1980s, the genre subsequently spread to North America and Europe, and crossed over into gay pornography. See Gay-for-pay. Arousal may be triggered by seeing the body movements or facial expressions of that person. However, the tradition of bondage naked milf magazines continues in the form of art books of bondage photographs, published by mainstream publishers such as Taschen.