The genres of pornography are based on the type momporn of activity featured and the category of participants, for example mateur pornography is a category of pornography that features models, actors or non-professionals performing without pay, or actors for whom this material is their only paid modeling work. Bondage/BDSM Bondage pornography features performers tied up or constrained in various ways. Urolagnia is a form of salirophilia in hentai sex which sexual excitement is associated with the sight or thought of urine or urination. Because the viewing of such films carried a social stigma, they were viewed at brothels, adult movie theaters, stag parties, at home, in private clubs and also at night cinemas. Rape pornography features performers simulating rape. This makes varying degrees of stimulation an integral part of oral sex for many men. Incest itself is largely taboo, and is a crime in many countries. New York photographer Irving Klaw also published illustrated adventure/bondage serials by fetish artists Eric Stanton, Gene Bilbrew, Adolfo Ruiz and others. Mutual masturbation, mutual manual stimulation of the genitals between partners, can be a substitute for sexual penetration. Since mammary intercourse is a non-penetrative sex act, the risk of passing a sexually transmitted infection that requires direct contact between the mucous membranes and pre-ejaculate or semen is greatly reduced. Preggo pornography features pregnant performers and may include erotic lactation as a fetish. 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. Reality pornography is professionally made porn which seeks to emulate the style of amateur pornography. When used as an alternative to gay bear porn penile-vaginal penetration, the goal may be to preserve virginity or to prevent pregnancy. Solo pornography recognized with AVN Awards include the All Alone series and All Natural: Glamour Solos.
