Immaculate Conception ?

Old but hilarious !!

A woman starts dating a doctor. Before too long, she becomes pregnant and
they don't know what to do. About nine months later, just about the time she
is going to give birth, a priest goes into the hospital for a prostate gland
infection. The doctor says to the woman,
"I know what we'll do. After I've operated on the priest, I'll give the baby
to him and tell him it was a miracle."
"Do you think it will work?" she asks.
"It's worth a try." he says. So, the doctor delivers the baby and then
operates on the priest.
After the operation he goes in to the priest and says, "Father, you're not
going to believe this.".
"What?" asks the priest, "what happened?".
"You gave birth to a child!".
"But that's impossible!" says the priest.
"I just did the operation," insists the doctor, "it's a miracle! Here's your
baby."
About fifteen years go by, and the priest realizes he must tell his son the
truth. One day, he sits the boy down and says,
"Son, I have something to tell you. I'm not your father." The son says,
"What do you mean, you're not my father?" The priest replies,
"I am your mother. The archbishop is your father.".