Use of the agreed safeword is seen by some as an explicit withdrawal of consent. Examples of heterosexual pornographic film series featuring creampies include Cream Filled Teens and Internal Cumbustion. New York photographer Irving Klaw also published illustrated adventure/bondage serials by fetish artists Eric Stanton, Gene Bilbrew, Adolfo Ruiz and others. However, bisexual pornography is often placed near the gay section in adult video stores, since many consumers are gay men. There is, however, no third party camera work involved. The most common male masturbation technique is simply to hold the penis with a loose fist and then to move the hand up and down the shaft. Mammary intercourse is a sex act, performed as foreplay or as non-penetrative sex, that involves the stimulation of the male penis by the female breasts and vice versa. Snowballing or snowdropping is the human sexual practice in which one person takes someone else semen into his or her mouth and then passes it to the mouth of the other, usually through kissing. Works in this genre may be considered adult for any number of reasons. Preggo pornography features pregnant performers and may include erotic lactation as a fetish. It has also been recommended young gay porn as a form of lesbian milfs foreplay or safer sex. Several hundred exclusively pegging films were produced, as well as twice as many bisexual and straight films with strap-on scenes. 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. Sexual orientation Pornography features an increasing variety of combinations of actors by their sexual orientation such as lesbian, gay, bisexual, and transsexuals in addition to traditional heterosexual roles. Pussing: British expression for an activity involving a consenting couple where the male partner watches the woman urinate otherwise undetected hentai sex in a semi-public place, usually a toilet cubicle at a pub, hotel, restaurant, theatre/cinema, office, club etc.