An 80 year old man walks into a fertility clinic with his 75 year old
 wife. He walks up to the doctor and tells him of their plan to have
 another child. 
 
 The doctor tells the man he'll need a sperm sample to see if that was
 possible. He hands the old man a plastic jar and tells him where to
go.
 The old boy takes his wife by the hand and heads for the room. 
 
 Two hours later the doctor was begining to wonder if they would ever
come
 out. The two finally emerged looking embarrassed. 
 
 "I tried with my left hand, I tried with my right hand, my wife tried
with
 her teeth in, and she tried with her teeth out," cried the man. "But
we
 still can't get the fucking lid off this thing!"