do it vs have a piss

do it

verb
  • To urinate. 

  • To be appealing or suitable. 

  • Used other than figuratively or idiomatically: see do, it. 

  • To have sex; make it. 

  • To do something exceptionally foolish or unacceptable. 

have a piss

How often have the words do it and have a piss occurred in a corpus of books? (source: Google Ngram Viewer )