assfuck vs butt sex

assfuck

noun
  • Sodomy, anal sex, an act of anal intercourse. 

  • A jerk; an obnoxious person. 

  • An act of stunning betrayal. 

verb
  • To betray. 

  • To engage in anal intercourse. 

butt sex

noun
  • Anal sex. 

How often have the words assfuck and butt sex occurred in a corpus of books? (source: Google Ngram Viewer )