Tommy was heading in to Mulligan's bar.

On the step outside he was accosted by a nun, Sister Marie, who said:-

"Surely a fine man like yourself is not going into this den of iniquity? Surely you're not going to waste your hard-earned cash on the devil's brew. Why don't you go home and feed and clothe your wife and children?"

"Hang on, Sister," spluttered Tommy. "How can you condemn alcohol out of hand? Surely it's wrong to form such a rash judgement when you've never tasted the stuff?"

"Very well," said Sister Marie. "I'll taste it just to prove my point. Obviously I can't go into the pub, so why don't you bring me some gin. Oh, and just to camouflage my intent, bring it in a cup not a glass!"

"OK," said Tommy and went into the bar.

"I'll have a large gin," he said to the barman. "And can you put it in a cup?"

"My God," said the barman, "that nun's not hanging around outside again is she?"