"Childless Couple" joke

There once was a husband and wife who were unable to have children. After consulting everyone who would listen to their problem, they were still unsatisfied. Finally, they consulted their family priest.
"My children," the priest began, "The Lord will listen to your prayers, and I am sure that you will be blessed with children shortly. In fact, I am planning an extended stay in Rome, and while I'm visiting the Vatican, I will light a candle for you."
"Thank you, Father, thank you!" said the couple.
Before leaving, the priest turned and said, "I am sure everything will work out just fine for you. My stay in Rome will be for quite some time-15 years. But when I return, I will be sure to pay you a visit."
And so, 15 years came and went, and the priest returned to the States.
While resting on his porch one mid-summer morning, he remembered the promise of paying a visit that he had made 15 years ago. So he made his way to their home, and upon arriving at the residence of the couple who'd sought his council years earlier, he rang the doorbell.
Sounds of crying and screaming children filled the air! Overjoyed by the thought that their prayers had been answered, he entered the house. More than a DOZEN children filled the house from top to bottom! In the midst of all the chaos, stood the wife.
"My dear," the priest said, "your prayers have been answered! And where is your husband? I wish to congratulate him too on your miracle!"
"He just left for Rome," she said in a very desperate tone.
"Rome? Why did he go to Rome?" asked the priest.
"To blow out that candle you lit!"