Twelve Catholic men went through priest school together. At the end of their years of training, they passed their written test. After the test was done, the bishop came to see them. He said,
"There is one more test you must pass before you are ready to become priests."
The bishop told the assembled men to strip naked and follow him to the next room. They did so.
In the next room, the bishop took a cardboard box down from the highest shelf, and took from it a handful of ribbons, with a small bell on the end of each. He went from man to man, tying a ribbon loosely around each man's penis. When he was done, he said,
"I'm going to bring a naked woman in here. She is going to dance in front of each of you. If your bell rings, you are not yet ready to become a priest."

The bishop left, and returned a moment later with the naked woman. She walked up to the first man and danced in front of him. He just stood there - no reaction.
She went to the second man, and got no reaction. She got no reaction from the third, fourth, etc. - on up to the eleventh man. Then she went to dance in front of the twelfth man, and he popped up so fast the ribbon came off his penis entirely, and fell to the floor a few feet in front of him.
This man, naturally embarrassed at having failed the test, walked forward two steps, and bent over to pick up the ribbon and bell.

Then all the other bells started to ring....

gasp!