A pregnant woman is about to give birth. The doctor has her on the
delivery table, legs up in the stirrups. Suddenly, he sees the top
of a head push through. Then the baby pops its head out and says
to the doctor, "Are you my dad?". 

The doctor says, "No, I am your doctor!". With that, the baby pops
right back inside. 

"Damn!", says the doctor. A short while later he sees the head push
through again. 

"Are you my dad?", asks the baby. 

"No, I am your doctor.", he replies. 

Once again the baby vanishes back into his mother's womb. 

The doctor turns to a nurse and says, "Nurse, get that baby's father
in here right away--we may have a situation on our hands!". Moments
later the baby's father is in the delivery room, and the baby's head
once again pops out. "Are you my dad?", the baby asks of the father. 

The father replies, "Yes, little baby, I am your father!" 

The baby then reaches up and begins poking his father in the forehead
with his index finger--"How do you like that?"