"You should be ashamed of yourself, young man! Drinking is a sin, and alcohol is the blood of the devil!"
Now Arthur got pretty annoyed about this, and went on the offensive. "How do YOU know, Sister?"
"My Mother Superior told me so."
"But have you ever had a drink yourself? How can you be sure that what you are saying is right?"
"Don't be ridiculous. Of course, I have never taken alcohol myself."
"Then let me buy you a drink. If you still believe afterwards that it is evil, I will give up drink for life."
"How could I, a Nun, sit outside this public house drinking?!"
"I'll get the barman to put it in a teacup for you. Then no one will know"
The Nun reluctantly agreed, and Arthur went inside to the bar.
"Another pint for me and a triple vodka on the rocks." Then he lowered his voice and said to the barman, "And could you put the vodka in a teacup?"
"Oh no! It's not that drunken Nun again is it?"