As of 2013, little analysis of this paraphilia has been reported in medical literature. Celebrity sex tapes are amateur or professionally-made recordings of sex acts, as performed by a celebrity and their partner. Female ejaculation is the expulsion of fluid by the paraurethral ducts through and around the human female urethra during or before an orgasm. The term hentai is never used in this context in Japanese. These scenes may either have the cameraman directly engaging in sex or merely filming others having sex. Creampie scenes depart from heterosexual pornographic convention in favor of anime hentai a depiction that more closely mimics sexual intercourse as performed in ordinary life; they have been called the counterimage of facials. Rough sex pornography is similar to pornography featuring sadomasochism, and typically features a Top who humiliates and/or momporn degrades a Bottom while being physically violent towards them. As a result, little in history was documented to give an accurate description of how female homosexuality is expressed. The person sat upon may be in bondage, sexually gay boy porn submissive, or simply held down by the body-weight of the other person. The term soft crush refers to the more common fetish surrounding videos involving inanimate objects or small invertebrates being crushed, while the term hard crush refers to such videos involving larger animals with vertabrae, and arguably more pain-susceptible animals . 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. Bisexual DVDs sell much better online than in adult video stores, possibly due to customers in stores feeling embarrassed to buy them. Other possibilities are possible, such as a man having sex with two women who are having sex with each other. Sadomasochism does not imply enjoyment through causing or receiving pain in other situations . 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.