In the Diagnostic and Statistical Manual of Mental Disorders , published by the American Psychiatric Association, it is classified under 302.89 – Paraphilia NOS and has no diagnostic criteria other than a general statement about paraphilias that says the diagnosis is made if the behavior, sexual urges, or fantasies cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. If one person is penetrated by two objects, it is generically gay sex video called double penetration . Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological milf fuck ultrasounds. In these research publications, it is suggested that real female ejaculation is the release of a very scanty, thick, and whitish fluid from the female prostate, while the squirting or gushing shown frequently in pornography is a different phenomenon, the expulsion of clear and abundant fluid, which has been shown to be a diluted fluid from the urinary bladder. Rainbow parties were covered on The Oprah Winfrey Show in 2003, and became the subject of a juvenile novel called Rainbow Party. Reality and voyeur pornography, animated videos, and legally prohibited acts also influence the classification of pornography. What seems clear from the historical record is that much of the lesbian material in pornographic texts was intended for a male readership. Use of the agreed safeword is seen by some as an hentai movies explicit withdrawal of consent. A bisexual threesome may involve a man having sex with a man and a woman, the woman having sex with a man and a woman, or all three having sex with each other. The cover can have hinges or be a separate part. Mammary intercourse is known as titty-fucking, titfuck, or a titjob in the United States, as well as tit wank or French fuck in the United Kingdom - the latter term dating back to the 1930s; while a more jocular equivalent is a trip down mammary lane. By comparison, gonzo pornography puts the camera right into the action, often with one or more of the participants both filming and performing sexual acts, without the usual separation between camera and performers seen in conventional porn and cinema.