People may experience pleasure from anal sex by stimulation of the anal nerve endings, and orgasm may be achieved through anal penetration – by indirect stimulation of the prostate in men, indirect clitoral/G-spot stimulation in women, and associated sensory nerves . Positions can also be chosen specifically for added effects such as increased humiliation, elevation and suspension. Cartoon pornography porno gay depicts illustrated or animated fictional characters in erotic and sexual situations. Today, pornographic films can be sold or rented on DVD, shown through Internet and special channels and pay-per-view on cable and satellite, and in adult theaters. Individual tastes and preferences in the area of sexuality may overlap among these areas, which are discussed separately here. These actors often play the top roles but this is not always the case, such as with Kristen Bjorn and some Bel Ami models. Some people get sexual pleasure by inserting objects, such as urethral sounds, into the urethra , a practice known as urethral play or sounding. The preference could be barefoot, high-heels, flip flops, and so on, depending on the fetishist. In these research publications, it is suggested that real female ejaculation is the release of a very scanty, thick, and whitish fluid from the female prostate, while the squirting or gushing shown frequently in pornography is a different phenomenon, the expulsion of clear and abundant fluid, which has been shown to be a diluted fluid from the urinary bladder. His most famous model was Bettie Page, who became the first celebrity of bondage film and photography. Some men place both hands directly on their penis during masturbation, while others may use their free hand to fondle their testicles, nipples, or other parts of their body. The purpose of this kind of agreement is primarily to encourage discussion and negotiation in advance, and then to document that understanding for the benefit of all parties. In general, as compared to conventional relationships, BDSM participants go to great lengths to negotiate the important aspects of their relationships in advance, and to take great care in learning about and following safe practices.