Mammary intercourse is said by Alex Comfort to produce mutual orgasm in women with sensitive breasts , and it was one of the nine substitute exercises for penetrative sexual activities, as detailed in the Paradis Charnels of 1903. The original definition of dogging – and which is still a closely related activity – is spying on couples having sex in a car or other public place. Female ejaculation is the expulsion of fluid by the paraurethral ducts through and around the human female urethra during or before an orgasm. Internal ejaculations, followed by big tit milf images of semen dripping from the anus, are sometimes depicted in bareback gay pornography, where they are referred to by the term breeding or the reverse money shot. Transsexual pornography features transwomen hentai sex performers, who typically have male genitalia and augmented female breasts . Women porn is often produced by women and aimed specifically at the female market - rejecting the view that men are turned on by porn but women only by a box of chocolates. A common way that these are depicted in a single scene is gay boy porn with one woman and two men performing together. Sadomasochism does not imply enjoyment through causing or receiving pain in other situations . 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. Unlike the traditional definition of the term, in fetish usage a cuckold is complicit in their partner sexual infidelity and takes masochistic sexual pleasure in it. The term hentai is never used in this context in Japanese. Celebrity sex tapes are amateur or professionally-made recordings of sex acts, as performed by a celebrity and their partner. While bondage is a very popular variation within the larger field of BDSM, it is nevertheless sometimes differentiated from the rest of this field. Shibari is a Japanese word that literally means to tie or to bind.