tunnel of love vs twat

tunnel of love

noun
  • The vagina. 

  • A carnival dark ride for couples in boats, either relaxing and romantic, or spooky (encouraging the couple to cling to one another). 

twat

noun
  • The vagina or vulva. 

  • A contemptible and stupid person, idiot. 

verb
  • To hit, slap. 

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