ONCE UPON A TIME THERE WERE TWO NUNS.
One of them was known as Sister Mathematical (SM).
The other was known as Sister Logical (SL).
It is getting dark and they are still far away from the safety of the convent.
SM: "Have you noticed that a man has been following us for the past 38 minutes? I wander what he wants."
SL: "It's logical. He wants to molest 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."
A LITTLE WHILE LATER.
SM: "It's not working."
SL: "Of course it's not working. The man did the only logical thing. He's walking faster too."
SM: "So what shall we do? At this rate he will be upon us in one minute."
SL: "The only logical thing to do is split up. He cannot follow us both."
The man decides to follow Sister Logical.
SM: arrives at the convent and is worried what has befallen SL>
Then SL arrives.
SM: "Thank God your here! Tell me what happened?"
SL: "The only logical thing happened. I started to run and he ran after me."
SM "AND?"
SL: The only logical thing happened. He caught me."
SM: "Oh dear! What did you do?"
SL: "The only logical thing to do. I lifted up my dress."
SM: "Oh, Sister! What did the man do?"
SL: "He did the only logical thing. He pulled his pants down."
SM: "Oh no! What happened then?"
SL: "Isn't it logical Sister? Nun with dress up can run faster than man with pants down."
And for those of you who thought it would have a dirty ending.
GO AND SIT ON THE NAUGHTY STOOL AND SAY TWO HAIL MARYS!