sleep together vs sleep with

sleep together

verb
  • To have sex with each other. 

  • To be intimate with each other in the same bed. 

  • Used other than figuratively or idiomatically: see sleep, together. 

sleep with

verb
  • To have sexual intercourse with. 

  • To share a bed or bedroom with. 

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