Many cultures describe pain as an aphrodisiac. Bottom and submissive are widely recognized terms for those partner in the relationship or activity who are, respectively, the physically receptive or controlled participants. The phrase is commonly found on porn sites. Softcore gay pornography also exists; it at one time constituted the genre, and may be produced as porn milf beefcake pornography for heterosexual female and homosexual male consumption. Sexual relations between women have been illustrated as well as narrated, but much of the written material from the early modern period has been destroyed. Mammary intercourse is a sex act, performed as foreplay or as non-penetrative sex, that involves the stimulation of the male penis by the female breasts and vice versa. The act may be carried out face to face, or head to tail, with the woman recommended to be on top if she has smaller breasts. There is no singular or archetypical behavior; therefore, a wide range of thought patterns and behaviors exist, but all tends to be a harmless and efficacious release from some kind of pressure. Depictions anime hentai of male and female masturbation are common in pornography, including gay pornography. These scenes may involve the female actor calling for the shot to be directed at some specific part of her body. Internal ejaculation shots are a comparatively recent development hot gay sex in pornography; they are not found in early pornographic films. Use of the agreed safeword is seen by some as an explicit withdrawal of consent. A sex party is a gathering at which sexual activity takes place. Examples include the Girls Gone Wild and Girls Who Like Girls Series. BDSM communities generally welcome anyone with a non-normative streak who identifies with the community; this may include cross-dressers, extreme body mod enthusiasts, animal players, latex or rubber aficionados, and others. BDSM is a variety of erotic practices involving dominance and submission, role-playing, restraint, and other interpersonal dynamics.