dangly bits vs erogenous zone

dangly bits

noun
  • Male genitalia, usually of a baby, child, or of a smaller than usual size; ironic reference to male genitalia. 

erogenous zone

noun
  • A part of the human body that is particularly responsive to sexual stimulation. 

How often have the words dangly bits and erogenous zone occurred in a corpus of books? (source: Google Ngram Viewer )