naughty vs triple-X

naughty

adj
  • Mischievous; tending to misbehave or act badly (especially of a child). 

  • Sexually provocative; now in weakened sense, risqué, cheeky. 

verb
  • To perform sexual acts upon. 

triple-X

How often have the words naughty and triple-X occurred in a corpus of books? (source: Google Ngram Viewer )