my ass vs my foot

my ass

intj
  • Indicates disapproval, disagreement, or disbelief, often with a tone of disregard, disdain, or disgust, referring to the buttocks. 

pron
  • I; me; myself; oneself in the third person. 

my foot

intj
  • Indicates disapproval, disregard, disdain, disgust or disbelief. 

  • Used other than figuratively or idiomatically: see my, foot. 

How often have the words my ass and my foot occurred in a corpus of books? (source: Google Ngram Viewer )