lust vs urge to merge

lust

noun
  • A feeling of strong desire, especially such a feeling driven by sexual arousal. 

verb
  • To look at or watch with a strong desire, especially of a sexual nature. 

urge to merge

noun
  • A strong desire to form intense emotional connections, stereotypically associated with lesbians. 

How often have the words lust and urge to merge occurred in a corpus of books? (source: Google Ngram Viewer )