A person may be sexually penetrated multiple times simultaneously. Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds. Reading or viewing pornography, sexual fantasy or other erotic stimuli may lead to a desire for sexual release such as by masturbation. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, gay fuck and their buttocks are objectified by porn as a result. If one person is penetrated by two objects, it is generically called double penetration . Mutual masturbation, mutual manual stimulation of the genitals between partners, can be a substitute for sexual penetration. Positions can also be chosen specifically for added effects such as increased humiliation, elevation and suspension. Gay pornography is the representation of sexual activity between males. For some people, non-penetrative sex is the primary sexual activity of choice above all others. Reality pornography is a genre of pornography where staged scenes, usually shot in cinéma vérité fashion, set up and precede sexual encounters. As the prostate is touch-sensitive, some directly stimulate momporn it using a well-lubricated finger or dildo inserted through the anus into the hentai videos rectum. Sadism describes sexual pleasure derived by inflicting pain, degradation, humiliation on another person or causing another person to suffer. Bukkake pornography involves a performer, usually female, onto whom several men or women ejaculate, usually on the face. The neologism pegging was popularized when it became the winning entry in a contest in Dan Savage Savage Love sex advice column, held after an observation was made that there was no common name for the act. Today, pornographic films can be sold or rented on DVD, shown through Internet and special channels and pay-per-view on cable and satellite, and in adult theaters. On the other hand, the masochist enjoys being hurt, humiliated, or suffering within the consensual scenario.