Note: This is one of many examples of religious humor that I have collected over the years. Where I have information about the original source, I have included it. Unfortunately, for most of these jokes and stories I do not have reliable authorship information. Like many jokes and urban legends, such information is difficult to trace.
There were two nuns...
SM: Have you noticed that a man has been following us for the past thirty-eight and a half minutes? I wonder what he wants.
SL: It's logical. He wants to rape us.
SM: Oh, no! At this rate he will reach us in 15 minutes at the most! What can we do?
SL: The only logical thing to do of course is to walk faster.
SM: It's not working.
SL: Of course it's not working. The man did the only logical thing. He started to walk faster, too.
SM: So, what shall we do? At this rate he will reach us in one minute.
SL: The only logical thing we can do is split. You go that way and
I'll go this way. He cannot follow us both.
Sister Mathematical arrives at the convent and is worried about what has happened to Sister Logical. Then Sister Logical arrives.
SM: Sister Logical! Thank God you are here! tell me what happened!
SL: The only logical thing happened. The man couldn't follow us both,so he followed me
SM: Yes, yes! But what happened then?
SL: The only logical thing happened. I started to run as fast as I could and he started to run as fast as he could.
SL: The only logical thing happened. He reached me.
SM: Oh, dear! What did you do?
SL: The only logical thing to do. I lifted my dress up.
SM: Oh, Sister! What did the man do?
SL: The only logical thing to do. He pulled down his pants.
SM: Oh, no! What happened then?
SL: Isn't it logical, Sister?
And for those of you who thought it would be dirty, say two Hail Marys!