As of 2013, little analysis of this paraphilia has been reported in medical literature. Interracial pornography typically employs ethnic and racial stereotypes in its depiction of performers and many of interracial pornographic films still include racial stereotypes, although the segregation of actors by race has diminished considerably. This may help them develop their orgasm, increase its pleasure, and may inspire them to masturbate on a more frequent basis. One or more of the participants may engage in autoerotic sexual activity, lesbian milfs such as masturbation, possibly without physical contact with the other participants. Homi Bhabha defined the idea of a racial fetish in contrast to the idea of the Freudian sexual fetish which he describes a denial of difference, where the male sees the female as a castrated male, seeing missing parts rather than a different anatomy. Actual spying may violate privacy and/or trespassing laws in many countries. It may also involve touching, rubbing, or pinching the nipples or other erogenous zones while masturbating. This may relate to fetishes such as voyeurism or cuckolding. Kinbaku means tight binding Kinbaku-bi which literally means the beauty of tight binding. Performers are usually clean-shaven, thinner and more effeminate than ones in mainstream gay pornography. Other possibilities are possible, such as a man having sex with two women who are having sex with each other. Such films continued to be produced hot gay sex but could only be distributed by underground channels. Within a BDSM or D/s context, facesitting can be an especially intense form of erotic humiliation. Since the 1980s, many practitioners and organizations have adopted the motto safe, sane and consensual, commonly abbreviated as SSC, which means that everything is based on safe activities, that all participants be of sufficiently sound/sane mind to consent, and that all participants do consent. Rough sex pornography is similar to pornography featuring 3d hentai sadomasochism, and typically features a Top who humiliates and/or degrades a Bottom while being physically violent towards them.