MATH PUZZLE: Can you replace...

She gets into the cab, and notices that the VERY handsome cab driver won't stop staring at her.
She asks him why he is staring.
He replies: "I have a question to ask you but I don't want to offend you."
She answers, "My son, you cannot offend me. When you're as old as I am and have been a nun as long as I have, you get a chance to see and hear just about everything. I'm sure that there's nothing you could say or ask that I would find offensive."
"Well, I've always had a fantasy to have a nun kiss me."
She responds, "Well, let's see what we can do about that: #1, you have to be single and #2, you must be Catholic."
The cab driver is very excited and says, "Yes, I'm single and Catholic!"
"OK" the nun says. "Pull in to the next alley."
The nun fulfills his fantasy, with a kiss that would make a hooker blush.
But when they get back on the road, the cab driver starts crying.
"My dear child," says the nun, "why are you crying?"
"Forgive me but I've sinned. I lied and I must confess, I'm married and I'm Jewish."
The nun says, "That's OK. My name is Kevin and I'm going to a Halloween party."