crown jewels vs male genitalia

crown jewels

noun
  • The male genitalia. 

  • The jewelry that accompany the office of rulership in a monarchy, i.e. crown, scepter, signet ring, etc. 

male genitalia

noun
  • collective or unspecific reference to the penis and testicles 

How often have the words crown jewels and male genitalia occurred in a corpus of books? (source: Google Ngram Viewer )