Scat or brown pornography features defecation, manipulation of feces, or consumption of feces, in reality or fantasy; a well-known example is the 2 Girls 1 Cup video. Often other friends and community members may witness the signing of such a document in a ceremony, and so parties violating their agreement can result in loss of face, respect or status with their friends in the community. It is a matter of subjective definition whether participation of a third person without physical contact constitutes a threesome. Threesome or 3some pornography features one man and two women . At these events, allegedly increasingly popular among adolescents, females wearing various shades of lipstick take turns fellating males in sequence, leaving multiple colours on their penises. Testosterone discourages fat storage in these areas. Furthermore, the DSM-IV-TR notes, Fantasies, behaviors, or objects are paraphilic only when they lead to clinically significant distress or impairment . Tentacle erotica features tentacled creatures raping or otherwise penetrating women or men. By comparison, gonzo pornography puts the camera right into the action, hentai videos often with one or more of the participants both filming and performing sexual acts, without the usual separation between camera and performers seen in conventional porn and cinema. These styles are much closer to the style of bondage scenes in mainstream television. Perhaps following the example set by gay pornography, they have become a popular subgenre within heterosexual pornography since the turn gaysex of the century, featuring both vaginal and anal ejaculations. The word shibari came into common use in the West at some point in the 1990s to describe the bondage art Kinbaku. Jeffrey Masson has even argued that incest mature milfs porn is the very nucleus of pornography — its prototypical form. 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.