balls vs fellatio

balls

noun
  • The testicles. 

  • A balls-up; a botched job. 

  • Masculinity, particularly strength, courage, and force of will; chutzpah; brazeness. 

  • Synonym of bollocks, nonsense. 

verb
  • Speaking or acting with bravado to achieve (something) 

  • To engage in sexual intercourse. 

adv
  • Very. Intensifier. 

fellatio

noun
  • The stimulation of the penis (or testicles) using the mouth. 

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