Biological anthropologist Helen B. A related term used in the genre is the term cougar, which implies an older woman as predator. Lesbian pornography typically features a wider range of appearances and body types than is typical of mainstream pornography. Female masturbation involves the stroking hot gay sex or rubbing of a woman vulva, especially her clitoris, with an index or middle fingers, or both. Gonzo pornography is a style of pornographic film that attempts to place the viewer directly into the scene. Among swinging couples, one of the two partners is often the driving force and the other is more passive-supportive of the addition of additional sex parties. Its gain in prominence has been attributed to its depiction in the film Pecker, which was released in 1998. 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. The volume of semen that is ejaculated depends on several factors, including the male health, age, degree of sexual excitement, and the time since his last ejaculation. Boots are seen as the perhaps most fetishistic of all footwear and boots may be the most popular fetish clothing attire. The name was coined from the title of the controversial book. Milking pornography features lesbian milfs lactating women being milked or milking themselves . 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. Some masturbate only using pressure applied to the clitoris without direct contact, for example by pressing the palm or ball of the hand against underwear or other clothing. Some prefer a particular type of clothing to urinate. 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 anime hentai was made that there was no common name for the act.