Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds. John Stagliano is considered to have started the gonzo pornography genre with his Buttman series of films. Some anthropologists and sociobiologists believe that breast fetishism derives from the breasts similarity to buttocks, but instead provide sexual attraction from the front of the body. Shotacon : Similar to gay boy porn Lolicon, this genre involves prepubescent or under-aged boys between the ages 6–12. Works in this genre may be considered adult for any number of reasons. Pornographic films are typically categorized as either softcore or hardcore pornography. Some aspects of the research community distinguish between female ejaculation and what is colloquially known as squirting or gushing. Coprophilia , also called scatophilia or scat , is the paraphilia involving sexual arousal and pleasure from feces. Detective magazines, comic books and early fetish magazines In the early anime hentai 20th century, Detective magazines covertly provided a way of publishing bondage imagery. This is commonly called double vaginal penetration or double stuffing. The actual height of the giantess within the fantasy may vary depending on the individual. In 1988, a sex tape caused significant damage to Rob Lowe career. 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. The term has also applied to other professions and even companies trying to appeal to a gay demographic. Reality and voyeur pornography, animated videos, and legally prohibited acts also influence the classification of pornography. It has since become popular enough with couples to be discussed during an episode of Sex and the City.