piss one's pants vs tinkle

piss one's pants

verb
  • To wet oneself; to urinate in one's own clothes while they are being worn. 

  • To be extremely frightened. 

  • To laugh uncontrollably. 

tinkle

verb
  • To urinate. 

  • To cause to tinkle. 

  • To indicate, signal, etc. by tinkling. 

  • To hear, or resound with, a small, sharp sound. 

  • To make light metallic sounds, rather like a very small bell. 

noun
  • A telephone call. 

  • Urine. 

  • A light metallic sound, resembling the tinkling of bells or wind chimes. 

  • An act of urination. 

How often have the words piss one's pants and tinkle occurred in a corpus of books? (source: Google Ngram Viewer )