A related term used in the genre is the term cougar, which implies an older woman as predator. The term has also applied to other professions and even companies trying to appeal to a gay demographic. The primary subjects of pornographic depictions are pornographic models, who pose for still photographs, and pornographic actors or porn stars, who perform in pornographic films. Some anthropologists and sociobiologists believe that breast fetishism derives from the breasts similarity to buttocks, but instead provide sexual attraction from the front of the body. To avoid soreness from this resulting friction, some may prefer to use a personal lubricant, masturbation cream or saliva during masturbation. The resulting consent and understanding is occasionally summarized in a written contract, which is an agreement of what can and cannot take place. They may regard it as an enhancing element of their sex lives or as gay sex video their primary form of sexual activity. Today, religions vary in their views of masturbation; some view it as a spiritually detrimental practice, some see it as not spiritually detrimental, and others take a situational view. Hermaphrodite, also known as herm, refers to pornography, typically hentai, that features persons with the genitalia of both sexes. In the Diagnostic and Statistical Manual of Mental Disorders , published by the American Psychiatric Association, it is classified under 302.89 – Paraphilia NOS and has no diagnostic criteria other than a general statement about paraphilias that says the diagnosis is made if the behavior, sexual urges, or fantasies cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. Studies among BDSM practitioners in the US have shown that about half of all men find the idea of bondage to be erotic; many women do as well. During anal sex, male pleasure can be particularly derived from the prostate, which can lead momsex to an orgasm and ejaculation. In Japan, point of view pornography is referred hentai porn to as hamedori .