pearl necklace vs stickpin

pearl necklace

noun
  • Used other than figuratively or idiomatically: see pearl, necklace. 

  • A sexual act whereby semen is ejaculated onto a partner's upper chest, breasts and/or throat. 

stickpin

noun
  • An ornamented pin used to secure a necktie's end flat against the shirt, a tie tack. 

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