A sub-set of gaping is the “‘tunnel cumshot”, wherein the male ejaculates directly into the gaping anus. The effect is to give the viewer the sense that they are experiencing the sex acts that they are watching, as opposed to simply watching others as a voyeur. This type of stimulation is typically all that is required to achieve momsex orgasm and ejaculation. A threesome is a common element of sexual fantasy. Facesitting is common among dominant and submissive individuals, for demonstrating superiority and for sexual gratification. Some diaper wearers wear their diapers for limited amounts of time, while others prefer to wear them on a 24-hour, seven-day schedule. Hamedori-type videos were produced from the beginnings of Japanese AV in the early 1980s. Various medical and psychological benefits have been attributed to a healthy attitude toward sexual activity in general and to masturbation in particular. Interracial gay sex video pornographic films have experienced an explosion in popularity, becoming one of the fastest-growing and biggest-selling genres. They are most often featured with hentai movies male partners, but are also featured with other transsexuals or cissexual women. Ethnic pornography is a genre of pornography that features performers of specific ethnic groups, or depictions of interracial sexual activity. It explores the more mental aspect of BDSM. Regardless of its origin, BDSM is used as a catch-all phrase to include a wide range of activities, forms of interpersonal relationships, and distinct subcultures. Bukkake videos are a relatively prevalent niche in contemporary pornographic films. Voyeur or peeping Tom pornography is usually more staged with the subjects aware of the cameras, sometimes openly including this exhibitionist awareness. If the penetrating objects are penises, this is sometimes called the spit roast or the Chinese finger trap. POV pornography involves camera angles designed to provide the viewer a view similar to that seen by one of the participants, whose face is never shown.