His most famous model was Bettie Page, who became the first celebrity mature milfs of bondage film and photography. Other objects such as ball point pens and thermometers are sometimes used, although this practice can lead to injury and/or infection. For circumcised males, on whom the glans is mostly or completely uncovered, this technique creates more direct contact between the hand and the glans. Works in this genre may be considered adult for any number of reasons. While some fantasize about a giantess who is slightly taller than himself, others are interested in giantesses that are hundreds or even thousands of feet tall. Use of the agreed safeword is seen by some as an explicit withdrawal of consent. Barebacking usually refers to a conscious and deliberate choice to forgo condoms. Contrary to the other two young gay porn types, B/D does not define the Tops and Bottoms itself, and is used to describe the general activities with either partner being the receiver and the giver. These actors often play the top roles but this is not always the case, such as with Kristen Bjorn and some Bel Ami models. Mammary intercourse is known as titty-fucking, titfuck, or a titjob in the United States, as well as tit wank or hentai movies 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. People may experience pleasure from anal sex by stimulation of the anal nerve endings, and orgasm may be achieved through anal penetration – by indirect stimulation of the prostate in men, indirect clitoral/G-spot stimulation in women, and associated sensory nerves . Today, religions vary in their views of masturbation; some view it as a spiritually detrimental practice, some see it as not spiritually detrimental, and others take a situational view. The industry generally refers to such films as adult films, which is part of adult entertainment. Bondage websites and bondage imagery in mainstream pornography As of 2003, specialist bondage magazines were mostly displaced by the availability of bondage material on the World Wide Web, and the presence of bondage imagery in mainstream pornographic magazines such as Nugget and Hustler Taboo magazine.