one-night stand

noun3

1. •
   A single sexual encounter between two individuals, where at least one of the partners has no immediate intention or expectation of establishing a longer-term sexual or romantic relationship.
2. •
   Either of the two partners involved in such a single sexual encounter.

   • She was a one-night stand he'd met at the gym, and Herschel couldn't remember her name. — 2009
3. •
   An occasion when a performer or team of them (especially in vaudeville) expects to perform at a theater for a single evening.

   • Again, when the affair is over, I catch a glimpse of myself running to catch a train for our next one-night stand. — 1916