Son: “Dad, did you get the results of the DNA test back?”
Dad: “Call me George.”
Son: “Dad, did you get the results of the DNA test back?”
Dad: “Call me George.”
This is a classic dad joke where the dad's response implies that he's not the son's biological father, and that the son should call him by his first name instead of "dad". It's funny because of the sudden and unexpected shift in the relationship and implies a possible secret or scandal.