Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having sexual intercourse with female characters. Sex parties may be organized to enable people to engage in casual sexual activity or for swinging couples or people interested in group sex to meet, but any gathering where sexual activity is anticipated can be called a sex party. Lesbianism has been a theme in erotic art since at least the time of ancient Rome, and many regard depictions of lesbianism to be erotic. Omorashi: The act of holding one own urine until the need to urinate is urgent, making another hold in their urine, or watching another person with an urgent need to urinate. These scenes may involve the female nude milfs actor calling for hentai sex the shot to be directed at some specific part of her body. Jerk off instruction features a performer encouraging or instructing the viewer to masturbate, often culminating in a countdown at the end of which the viewer is invited to induce orgasm. The prostate gland is one of the organs that contributes fluid to semen. Reality pornography is professionally made porn which seeks to emulate the style of amateur pornography. Its primary gay bear porn goal is sexual arousal in its audience. For much of the history of cinema and television, lesbianism was considered taboo, though since the 1960s it has increasingly become a genre in its own right. Sadomasochism is practiced in isolation relatively rarely, though some masochists report biting, pinching, or even stun-gunning themselves as a prelude to, or as part of, masturbation. Since the 1980s, many practitioners and organizations have adopted the motto safe, sane and consensual, commonly abbreviated as SSC, which means that everything is based on safe activities, that all participants be of sufficiently sound/sane mind to consent, and that all participants do consent. Rape pornography features performers simulating rape. Body parts including fingers, tongue and penis may be used for anonymous oral, vaginal and/or anal intercourse.