Most soft crush fetishists avoid being placed under the same label as hard crush fetishists, believing that crush films with mature milfs larger animals give the entire group a bad label. Entacle erotica describes a type of pornography most commonly found in Japan which integrates traditional pornography with elements of bestiality and a fantasy, horror, or science-fiction theme. One or more of the participants may engage in autoerotic sexual activity, such as masturbation, possibly without physical contact with the other participants. These scenes may either have the cameraman directly engaging in sex or merely filming others having sex. This style of hentai videos filming is in contrast to having a separate, third-person camera crew filming all the action. Performers are usually clean-shaven, thinner and more effeminate than ones in mainstream gay pornography. This fetish sometimes originates from childhood memories of needing, or of seeing another needing, to urinate. As in B/D, the declaration of the Top/Bottom may be required, though sadomasochists may also play without any Power Exchange at all, gay movies with both partners equally in control of the play. Pornography is often referred to as porn and a pornographic work as a porno. In more vigorous forms of fisting, such as punching or punchfisting, a fully clenched fist may be inserted and withdrawn slowly. 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. The related term twinkle-toes, which implies that a man is effeminate, tends to be used in a derogatory manner. The name of the practice, when it is done in a repeated in-and-out motion, is derived from its passing resemblance to the dipping of a tea bag into a cup of hot water as a method of brewing tea. The anus has a relatively high concentration of nerve endings and can be an erogenous zone, and the receiver may receive pleasure from external anal stimulation.