These are one of the funniest kind of jokes because the Medical profession is otherwise a serious profession.
This older man was on the operating table awaiting surgery and he insisted that his son, a renowned surgeon, perform the operation.
As he was about to receive the anesthesia he asked to speak to his son.
"Yes Dad, what is it?"
"Don't be nervous, son, do your best and just remember, if it doesn't go well, if something happens to me... your mother is going to come and live with you and your wife...."