So Father O'Leary was walking home from Mass, when he saw Mrs. O'Malley walking home as well. Since Mrs. O'Malley was a newlywed, Father O'Leary struck up a conversation with her.
"So, Mrs. O'Leary, how is your husband on this fine morning?"
"Oh Father, he's working to provide a home for us."
"Ah, grand. And do you have any children yet?"
"No Father, none yet."
"Well, as I'm going to Rome for my next duty next month, I'll light a candle for you to have children and have a grand large family!"
So Father O'Leary goes to Rome, and lights a candle for the O'Malley family, and finally makes it back to Ireland three years later. And going to his old church, he sees Mrs. O'Malley with a stroller, and greets her with a joyous prayer.
"Ah, Mrs. O'Malley! I see you have children, praise be to God! Tell me, how many young children do you have?
"We have seven children, Father. Two sets of twins and one set of triplets!"
"Oh, that's grand! And where is Mr. O'Malley?"
"He's gone to Rome, Father.... to blow out that fookin' candle!"