The term is typically used by the cinematographer within the narrative framework of a pornographic film, and since the 1970s has become a leitmotif of the hardcore genre. It is typically animated pornography, as the legal age to be featured in a pornographic film in Japan is 18. Such documents have not been recognized as being legally binding, nor are they intended to be. This is commonly called double vaginal penetration or double stuffing. Detective magazines, comic books and early fetish magazines In the early 20th century, Detective magazines covertly provided a way of publishing bondage imagery. Voyeur pornography may also include shots of topless women on topless beaches who are unaware of the cameras but may legally be photographed due to the public setting. On May 27, 2010 the television program The Doctors discussed the topic with dozens 3d hentai of teens, parents, and professionals. Diaper fetishism is totally independent from pedophilia as the wearer derives pleasure only from the diaper and/or use of it. Lesbian pornography typically features a wider range of appearances and body types than is typical of mainstream pornography. A woman can use a secondary vibrator, between the dildo and her genitals, to get pleasure from pegging. Foot fetishism has been defined as a pronounced sexual interest in the feet or footwear. Particular areas and processes of the body that change during pregnancy may also become the focus of psychological investment, but nudity or sexual activity is not always essential, and in some cases actual pregnancy is not necessary to invoke arousal. Internal ejaculation shots are a comparatively recent development gay twinks in pornography; they are not found in early pornographic films. There is, however, no third party camera work involved. A scene where many women have sex with one man is referred to as a reverse momsex gang-bang. Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds.