dirty pillow vs titty

dirty pillow

noun

  • A breast, especially a woman's breast. 

  • Used other than figuratively or idiomatically: see dirty, pillow. 

titty

noun

  • A breast. 

  • A sister or girl. 

  • A nipple. 

  • A kitten. 

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