Since development and pronunciation of the buttocks begins at menarche and declines with age, full buttocks are also a symbol of youth. The term applies to the depiction of the act rather than the act itself, and so does not include live exhibitions like sex shows and striptease. Normal quantities of ejaculate range from 1.5 to 5.0 milliliters . Reality pornography is professionally made porn which seeks to emulate the style of amateur pornography. Tentacle rape or shokushu goukan is found in some horror or hentai titles, with tentacled creatures having sexual intercourse with female characters. Actual upskirt or downblouse shots may violate privacy laws in some countries. The smotherbox is placed on a stable surface. It is typically animated pornography, as the legal videos gays age to be featured in a pornographic film in Japan is 18. There may be more than two participants; both group sex and gang banging can be included. As of 2013, little analysis of this paraphilia has been reported in medical literature. Mammary intercourse is a sex act, performed as foreplay or as non-penetrative sex, that involves the stimulation of the male penis by the female breasts and vice versa. The phrase buttered bun is sometimes used to refer to the owner of the orifice in question. A celebrity may allow such hentai videos a recording to surface willingly, as part of a publicity stunt. Bondage websites and bondage imagery in mainstream pornography As of 2003, specialist bondage magazines were mostly displaced by the availability of bondage material on the World Wide Web, and the presence of bondage imagery in mainstream pornographic magazines such as Nugget and Hustler Taboo magazine. The term Asiaphile is sometimes used to describe the same phenomenon as is yellow fever . Comic books often featured characters being tied up and tying others up, particularly in damsel in distress plots. Its primary goal is sexual arousal in its audience. A female dominant in a master/slave relationship is often termed a Mistress, not to be confused with the colloquial usage of mistress as a kept sexual partner without a similarly formalized nude milfs power relationship.