one-night stand
noun [ C ] uk/ˌwʌn.naɪt ˈstænd/ us/ˌwʌn.naɪt ˈstænd/
(SEX)
一夜情，一夜风流；一夜情人，露水夫妻
a sexual relationship that lasts for only one night, or a person who you have had this type of relationship with
(PERFORMANCE)
（在某地的）单场演出
a performance that happens only once in a particular place