Just in case anyone is unfamiliar with the term.

https://en.m.wikipedia.org/wiki/One-night_stand

A one-night stand is a single sexual encounter without an expectation of further relations between the sexual participants. This is regardless of whether a single encounter was originally intended by either participant to be a one-night stand, or whether further relations between the participants subsequently occur. Critics of the practice describe it as "sexual activity without emotional commitment or future involvement".[1]

Reasons per Wikipedia...

A one-night stand can occur for different reasons, which vary between people. Examples of one-night stand participants include young adults exploring their sexuality; single people seeking to engage in sexual activity without any sort of commitment or relationship; or married people who desire extramarital sex without disturbing their marriage or family relationships through extramarital romantic relations. A one-night stand may be pre-planned, in which at least one of the participants intended for the sexual encounter to be a one-night stand prior to participating.