double date vs two-timing

double date

noun

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

verb

  • To go on a double date. 

two-timing

noun

  • The practice of being sexually or romantically unfaithful. 

adj

  • Sexually or romantically unfaithful. 

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