Casual sex is sexual activity that takes place outside a romantic relationship and implies an absence of commitment, emotional attachment, or familiarity between sexual partners. Examples are sexual activity while casually dating, one-night stands, prostitution or swinging. Practices Single encounters A one-night stand is a single sexual encounter between individuals, where at least one of the parties has no immediate intention or expectation of establishing a longer-term sexual or romantic relationship. Anonymous sex is a form of one-night stand or casual sex between people who have very little or no history with each other, often engaging in sexual activity on the same day of their meeting and usually never seeing each other again afterwards. Social sex The terms friends with benefits and booty call describe situations in which a person has sex with someone they generally consider a friend or someone they are fairly close to. They are not in an exclusive romantic relationship. The involved parties may have a degree of emotional attachment but do not want, for whatever reason, to have "strings attached". A 2011 study, published in The Journal of Sex Research, found that two out of five single women and one out of five single men in "friends with benefits" relationships hoped that their relationship would eventually turn into a full-fledged romance. This stands in contrast to swinger couples who are already in long-term relationships and are only seeking compatible friends with whom they can engage in recreational sex. Recreational sex can take place in an open marriage, among swingers (where sex is viewed as a social occasion), or in an open relationship. Hooking up A "hookup" (colloquial American English) is a casual sexual encounter involving physical pleasure without necessarily including emotional bonding or long-term commitment. It can range from kissing (for example, making out) to other sexual activities. The practice of hooking up became a widespread among young people in the 1980s and 1990s. Researchers say that what differentiates hooking up from casual sex in previous generations of young people is the "virtual disappearance" of dating, which had been dominant from the postwar period onwards. In more modern times, rather than dating, casual sex is the primary path for young people into a relationship. With the use of apps becoming more common it has become easier to hook up or meet others for sexual activity. With students, studies have shown that the group most likely