play house vs room together

play house

noun
  • A child's toy domestic dwelling, either for dolls or large enough for the child to enter. 

verb
  • To live as if married without actually being legally married. 

  • To pretend to be a family in the household, acting out housekeeping and different family roles. 

room together

How often have the words play house and room together occurred in a corpus of books? (source: Google Ngram Viewer )