share a bed vs sleep together

share a bed

verb
  • To engage in sexual intercourse (with someone). 

  • Used other than figuratively or idiomatically: see share, bed. 

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. 

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