It is sometimes described as a sexual fantasy, by women or men, depicting an exhibitionist or physique worship scenario. As of 2013, little analysis of this paraphilia has been reported in medical literature. A sub-set of vaginal fisting attempts to photograph the female cervix immediately after the fist is removed from the now-gaping vagina. Mutual masturbation can be practiced by males or females in pairs or groups with or without actually touching another person as indicated by the following examples of contact versus non-contact scenarios: Non-contact mutual masturbation Two people masturbating in the presence of each other but not touching. 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 is mutual consent that makes a clear legal and ethical distinction between BDSM and such crimes as sexual assault or domestic violence. Body parts including fingers, tongue and penis may be used for anonymous oral, vaginal and/or anal intercourse. Pornography in Japan is large and intertwined business gaysex of adult entertainment with unique characteristics that hentai videos readily distinguish it from western pornography. It spawned numerous sequels, several of which won adult film awards. The term lesbian is also used with regard to sexual identity or sexual behavior, regardless of sexual orientation, or as an adjective to characterize or associate nouns with female homosexuality or same-sex attraction. Animal masturbation has been observed in many species, both in the wild and in captivity. BDSM actions can often take place during a specific period of time agreed to by both parties, referred to as play, a scene or a session. Actual spying may violate privacy and/or trespassing laws in many countries. Saliva pornography involves salivation and saliva. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just porn milf before ejaculating.