My Late Grandfather's Favorite Joke: The proctologist and the cardiologist

My Late Grandfather's Favorite Joke: The proctologist and the cardiologist

A proctologist and a cardiologist are closing their tab.

The bartender brings the check.

The proctologist says "they're on me" while reaching into his shirt-pocket.

He proceeds to pull out a thermometer and exclaims, "Great, some *ass-hole* walked off with my pen"!