side bitch vs skivvy

side bitch

noun
  • A mistress; a woman one dates in addition to his girlfriend or wife, usually in secret. 

skivvy

noun
  • A prostitute. 

  • A close-fitting, long-sleeved T-shirt with a rolled collar. 

verb
  • To perform menial work; to do chores, like a servant. 

How often have the words side bitch and skivvy occurred in a corpus of books? (source: Google Ngram Viewer )