casual sex vs one-night stand

casual sex

noun
  • Sexual activity that is undertaken without commitment, emotional attachment or personal familiarity between the participants involved. 

one-night stand

noun
  • 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. As the phrase implies, the relationship lasts for only one night. 

  • Either of the two partners involved in such a single sexual encounter. 

  • An occasion when a performer or team of them (especially in vaudeville) expects to perform at a theater for a single evening. 

How often have the words casual sex and one-night stand occurred in a corpus of books? (source: Google Ngram Viewer )