one–night stand

one–night stand noun
plural one–night stands
one–night stand
noun
plural one–night stands
Britannica Dictionary definition of ONE–NIGHT STAND
[count]
1 
: a situation in which you have sex with someone once and you do not continue in a relationship afterwards
also : one of the people involved in this situation
2 
: a performance of a play, concert, etc., that is given only once in a particular place