Reminds me of a similar joke.

Nun got on a bus. Some guy said he wanted to have sex with her. She said she was married to god, and that can't happen. The bus driver overheard the conversation, and told the guy that she prays at the cemetary at midnight every night. Go there tell her you are god, and she will probably have sex with you. He found her just like the bus driver said praying. He said he was god and wants to have sex with her. She said okay but can we do anal so I still have my virginity? He agreed. After the deed was done the guy goes "haha I'm the guy from the bus". Nun turns around and says "haha I'm the bus driver".