There are currently no known laws forbidding the crushing of objects and insects, however the production or trade of crush erotica involving live vertebrates is condemned by animal rights activists and is illegal in many countries, including the United States and Great Britain. A sexual fetish may be regarded as an enhancing element to a romantic/sexual relationship achieved in ordinary ways or as a mental disorder/disorder of sexual preference if it causes significant psychosocial distress for the person or has detrimental effects on important areas of their life. The interaction between tops and bottoms—where physical or mental control of the bottom is surrendered to the top—is sometimes known as power exchange, whether in the context of an encounter or a relationship. Discipline often incorporates sadomasochistic gay movies aspects, though some sadomasochists distance themselves from D/s practices such as punishment. In the 1970s, the hardcore pornography genre introduced the stereotypical cumshot scene as a central element of the hardcore film, in which the male actor ejaculates in a way ensuring maximum visibility of the act itself. While most tentacle erotica is animated, there are also a few live-action movies. Spanking or whipping momsex pornography involves spanking hentai porn or whipping, generally of the buttocks, with the hand or with other objects such as belts, switches, paddles, brushes, or whips. 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. Bukkake pornography usually depicts numerous men having sex with one woman, with multiple, usually 10 or more, men ejaculating on the female face. Although interracial pornography theoretically can apply to depictions of sexual activity between performers of any different racial groups, the term is most commonly used for heterosexual sex acts between black and white performers. An orgy is a gathering where guests freely engage in open and unrestrained sexual activity or group sex; and a bunga bunga orgy is an orgy in which participants have sex underwater, such as in a swimming pool or a hot tub.