In human sexuality, a threesome is "a sexual interaction between three people whereby at least one engages in physical sexual behaviour with both the other individuals".[1] While the term threesome typically refers to sexual activity involving three participants,[1][2][3] it has at times been used to refer to a long-term domestic relationship, such as polyamory or a ménage à trois.[4]
A threesome is a form of group sex that typically occurs in private settings, such as spontaneous sexual activity among three friends or in the context of casual sex or a hook up. A threesome may occur in specific contexts or environments that allow for sex, such as swingers events, orgies, or sex parties.[citation needed] Threesomes are a common element of sexual fantasy,[5][6] and are widely depicted in pornography.
^LEHMILLER, JUSTIN J. (2018). TELL ME WHAT YOU WANT: The Science of Sexual Desire and How It Can Help You Improve Your Sex Life. ROBINSON. ISBN978-1-4721-4223-8. OCLC1013584575.