Transgender pornography features performers who cross-dress for sexual gratification, either for themselves or for their partners. Interactive pornography, available in CD-ROM and DVD format, allows the viewer to select the particular acts performed at any one time, sometimes with the camera providing a first person view. The strategies and tactics that are used to smuggle one of the couple into and out of the toilet undetected are as important or almost as important as the urination. Because the viewing of such films carried a social stigma, they were viewed at brothels, adult movie theaters, stag parties, at home, in private clubs and also at night cinemas. Transsexual pornography is a genre of pornography. Originating videos gays in Japan in the 1980s, the naked celebrities genre subsequently spread lesbian milfs to North America and Europe, and crossed over into gay pornography. The Silent Duck, also called Duck-Billing, gayporno is the technique often used in which the person engaging in hand insertion shapes the hand to resemble a duck beak. Diaper pornography involves performers wearing diapers, sometimes with an adult performer acting in the role of a caretaker. The scenario is a genre of erotica, which on the internet is sometimes abbreviated to CMNF, and may involve sexual and nonsexual erotic scenarios. Celebrity sex tapes are amateur or professionally-made recordings of sex acts, as performed by a celebrity and their partner. In more vigorous forms of fisting, such as punching or punchfisting, a fully clenched fist may be inserted and withdrawn slowly. Other fetish Bareback pornography features performers who are not wearing condoms. Bondage websites and bondage imagery in mainstream pornography As of 2003, specialist bondage magazines were mostly displaced by the availability of bondage material on the World Wide Web, and the presence of bondage imagery in mainstream pornographic magazines such as Nugget and Hustler Taboo magazine. What seems clear from the historical hentai porn record is that much of the lesbian material in celebrity porn pornographic texts was intended for a male readership.