double date vs fling

double date

noun
  • A (romantic) date that two couples go on together. 

verb
  • To go on a double date. 

fling

noun
  • A short romantic, oftentimes sexual, relationship. 

  • An act of throwing, often violently. 

  • An attempt, a try (as in "give it a fling"). 

  • A lively Scottish country dance. 

  • An act or period of unrestrained indulgence. 

  • An act of moving the limbs or body with violent movements, especially in a dance. 

verb
  • To throw with violence or quick movement; to hurl. 

How often have the words double date and fling occurred in a corpus of books? (source: Google Ngram Viewer )