Bisexual pornography is a genre of pornography which most typically depicts one woman and two men who all perform sex acts on each other. It spawned numerous sequels, several of which won adult film awards. Comic books often featured characters being tied up and tying others up, particularly in damsel in distress plots. A female dominant in a master/slave relationship is often termed a Mistress, not to be confused with the colloquial usage of mistress as a kept sexual partner without a similarly formalized power relationship. It is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual nude milfs assault or domestic violence. Transsexual people Transman pornography features performers who were born female and who medically transitioned to male. Softcore gay pornography also exists; it at one time constituted the genre, and may be produced as beefcake pornography for heterosexual female and homosexual male consumption. In pornography, depictions of lesbian sex form a popular subgenre, directed toward a male heterosexual and female homosexual naked celebrities audience. Emetophilia hentai sex pornography involving vomiting and adult anime gagging. It is sometimes combined with BDSM features. Lesbian pornography made for women is usually made by women, and usually features women who identify as lesbian or bisexual. Examples include the Girls Gone Wild and Girls Who Like Girls Series. This technique may include the use of a simulacrum, or artificial vagina. Some techniques which may work for one individual can be difficult or uncomfortable for another. If ejaculation is onto the other person face it can be called a facial. Stimulating the prostate from outside, via pressure gay twinks on the perineum, can be pleasurable as well. The genres of pornography are based on the type of activity featured and the category of participants, for example gay sex video 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.