An elderly couple walk into a doctor's office

An elderly couple walk into a doctor's office. The man tells the
doctor, "Doctor, we want
to have a baby." The doctor replies,"At your age I don't think it's
possible, but I'll give
you a jar, come back in a few days with a sperm sample." So the couple
comes back a few
days later.They give the doctor an empty jar. The doctor says,"I was
afraid of this." The
old man says,"No, it's not what you think. I tried it with my left
hand. I tried it with my
right hand. She tried it with her left hand. She tried it with her
right hand. She tried it with
her teeth in. She tried it with her teeth out. But we couldn't get the
lid off the jar."