"Blow out !!" joke

Mrs. Jones was walking down a Street in Dublin, and coming in the opposite direction was Father O'Rafferty.
"Hello," said the Father, "And how are you Mrs. Jones? Didn't I marry you two years ago?"
She replied "You did that, Father."
"And are there any little ones yet?"
"No, not yet, Father," she said.
"Well now, I'm going to Rome next week, and I'll light a candle for you."
"Oh, thank you, Father." And away she went.
Several years later they met again.
"Well now, Mrs. Jones," said the Father, "How are you?"
"Oh, very well," she said.
"And tell me," he said, "have you any little ones yet?"
"Oh yes, Father. I've had three sets of twins, and four singles - ten in all.
"Now isn't that wonderful !!!, " he said "And how is your fine husband?"
"Oh," she said, "he's gone to Rome to blow out your candle ..!!!"