Body parts including fingers, tongue and penis may be used for anonymous oral, gaysex vaginal and/or anal intercourse. Men and women may masturbate until they are close to orgasm, stop for a while to reduce excitement, and then resume masturbating. While bondage is a very popular variation within the larger field of BDSM, it is nevertheless sometimes differentiated from the rest of this field. To tea bag is a slang term for the sexual act of a man placing his scrotum in the mouth of a willing sexual partner for pleasure or onto the face or head of another person. The naked milf essence of voyeurism is the observing but may also involve the making of a secret photograph or video of the subject during an intimate activity. One or more of the participants may engage in autoerotic sexual activity, such as masturbation, possibly without physical contact with the other participants. Especially popular in post-World War 2 Japanese culture. Using the term shemale anime hentai for a transsexual woman often implies that she is working in the sex trade. The name of the practice, when it is done in a repeated in-and-out motion, is derived from its passing resemblance to the dipping of a tea bag into a cup of hot water as a method of brewing tea. Unlike erotic films, pornographic films contain explicit sexuality and do not claim any artistic merit. The sub-genres usually conform to certain conventions, and each may appeal to a particular audience. 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. The fetish centers around this fantasy portrayal. A pearl necklace is a slang term referring to a sexual act in which a man ejaculates semen on or near the neck, chest, or breast of another person. Participants usually derive pleasure from this, even though many of the practices—such as inflicting pain or humiliation or being restrained—would be unpleasant under other circumstances.