Some aspects of the research community distinguish between female ejaculation and what is colloquially known as squirting or gushing. Sigmund Freud considered foot binding as a form of fetishism. Foot fetishism has been defined as a pronounced sexual interest in the feet or footwear. Both sexes sometimes apply lubricating hentai movies substances to intensify sensation. People may experience pleasure from anal sex by stimulation of the anal nerve endings, and orgasm may be achieved through anal penetration – by indirect stimulation of the prostate in men, indirect clitoral/G-spot stimulation in women, and associated sensory nerves . Medical pornography involves sexualized medical, often fake, including gynecological pelvic examinations, rectal examinations, and pelvic or gynecological ultrasounds. For some people, non-penetrative sex is the primary sexual activity of choice above all others. Reality and voyeur pornography, animated videos, and legally big tit milf prohibited acts also influence the classification of pornography. Mammary intercourse is known as titty-fucking, titfuck, or a titjob in the United States, as well as tit wank or French fuck in the United Kingdom - the latter term dating back to the 1930s; while a more jocular equivalent is a trip down mammary lane. Typically featured are hitting, choking, name-calling and hair-pulling. A scene where many women have sex with one man is referred to as a reverse gang-bang. It has since become popular enough with couples to be discussed during an episode of Sex and the City. Today, pornographic films can be sold or rented on DVD, shown through Internet and special channels and pay-per-view on cable and satellite, and in adult theaters. Many cultures describe pain as an aphrodisiac. When the interest in a particular subject is obsessive, the behavior may be described young gay porn as stalking. Solo performances in gay pornography have been described in 1985 as either or both active and/or passive , whereas female solo performances are said to be exclusively passive .