Oral sex pornography frequently features a person performing fellatio, and less frequently cunnilingus. Rape pornography features performers simulating rape. Bukkake is a sex act portrayed in pornographic films, in which several men ejaculate on a woman, or another man. Older names for a pornographic gay cock film include stag film, and blue movie. Multiple men and women Bisexual pornography features one woman and two men who all perform sex acts on each other. Pornography is often distinguished from erotica, which consists of the portrayal of sexuality with high-art aspirations, focusing also on feelings and emotions, while pornography involves the depiction of acts in a sensational manner, with the entire focus on the physical act, so as to arouse quick intense reactions. Pussing: British expression for an activity involving a consenting couple where the male partner watches the woman urinate otherwise undetected in a semi-public place, usually a toilet cubicle at a pub, hotel, restaurant, theatre/cinema, office, club etc. The first explicit pegging scene is believed to have been in the 1975 pornographic film The Opening of Misty Beethoven. A woman can use a secondary vibrator, between the dildo and her genitals, to get pleasure from pegging. 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. The niche popularity grew significantly in the latter half of the first decade of the 2000s. Other objects such as ball point pens and thermometers are sometimes used, although this practice can lead to injury and/or infection. The concept of lesbian, to differentiate women with a shared sexual orientation, is a 20th-century construct. Particular areas and processes of the body that change during pregnancy may also become the focus of psychological investment, but nudity or sexual activity is not always essential, and in some cases actual pregnancy is not necessary hentai sex to invoke arousal. The term sadomasochism is derived from the words sadism porn milf and masochism .