gratify vs lead on

gratify

verb
  • To make content; to satisfy. 

  • To please. 

lead on

verb
  • to encourage with the illusion of a romantic relationship. 

  • to mislead, to try to make someone believe a lie. 

  • Used other than figuratively or idiomatically: see lead, on. 

How often have the words gratify and lead on occurred in a corpus of books? (source: Google Ngram Viewer )