Concerted deployed sexual rejection exercised on the partner can be an aspect of Dominance and Submission as well. The term BDSM dates back to 1969; however, the origin of the term BDSM is unclear and is believed to have been formed either from joining the term B&D with S&M , or as a compound initialism from B&D, D&S , and S&M. In the gay pornography industry, which lesbian milfs uses amateurs as well as professional actors, the term gay-for-pay refers to actors labeled or believed to be straight but who engage in same-sex sexual activities for money. There is, however, no third party camera work involved. If one person is penetrated by two objects, it is generically called double penetration . Transgender pornography features performers who cross-dress for sexual gratification, either for themselves or for their partners. It is also followed by dedicated industry publications and trade groups as well as the mainstream press, private organizations , government agencies, and political organizations. Older gay cock names for a pornographic film include stag film, and blue movie. Preggo pornography features pregnant performers and may include erotic lactation as a fetish. Some men also enjoy anal stimulation, with fingers or otherwise, without any prostate stimulation. Rape pornography features performers simulating rape. Being forced to wear diapers as a form of humiliation is sometimes a behavior encountered in sexual masochism. Use of the agreed safeword is seen by some as an explicit withdrawal of consent. For instance, Amateur Allure has a trademark shot where the sexually performing cameraman circles a handycam around the sexually performing model head. 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 hentai videos magazines such as Nugget and Hustler Taboo magazine. Contrary to the other two types, B/D does not define the Tops and Bottoms itself, and is used to describe the general activities with either partner being the receiver and the giver.