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. A related term used in the genre is the term cougar, which implies an older woman as predator. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, and their buttocks gay twink porn are objectified by porn as a result. Rubber pornography involves rubber, latex, and similar materials. In some creampie films, both gay and straight, intercourse and internal ejaculation are followed by performers licking up the semen that has dripped from their bodies. Swinging can take place in various contexts, ranging from a spontaneous sexual activity at an informal social gathering of friends to a regular social gathering in a sex club or residence. In Japanese, the term describes any type of perverse or bizarre sexual desire or act; it does not represent a genre of work. Women with women Main article: Lesbianism in erotica: Lesbianism in contemporary pornography Lesbian or girl-girl momporn pornography features women engaged in sex together, but is typically aimed at a male audience. Special forms include erotic roleplay like ageplay, in which a difference in age, either real or enacted, formulates the background; or petplay. In POV porn, the shooting style is generally similar to gonzo pornography, with the person receiving sexual gratification holding the camera him or herself—aiming it down at the actress or actor who is performing the sex act. The most common male masturbation technique is simply to hold the penis with a loose fist and then to move the lesbian hentai hand up and down the shaft. It is the most common form of sexual fetishism for otherwise non-sexual objects or body parts. Sadism describes sexual pleasure derived by inflicting pain, degradation, humiliation on another person or causing another person to suffer. Cartoon pornography includes, but is not limited to, hentai and parody renditions of famous cartoons and comics.