"The Key to Heaven"

It was time for Father John's Saturday night bath, and the young nun
Sister Magdalene had prepared the bath water and towels just the way
the old nun had instructed. 
Sister Magdalene was also instructed not to look at Father John's
nakedness if she could help it, do whatever he told her to do, and
pray. 
The next morning the old nun asked Sister Magdalene how the Saturday
night bath had gone. 
"Oh, sister," said the young nun dreamily, "I've been saved." 
"Saved? And how did that fine thing come about?" asked the old nun. 
"Well, when Father John was soaking in the tub, he asked me to wash
him, and while I was washing him he guided my hand down between his
legs where he said the Lord keeps the Key to Heaven." 
"Did he now?" said the old nun evenly. 
Sister Magdalene continued, "And Father John said that if the Key to
Heaven fit my lock, the portals of Heaven would be opened to me and I
would be assured salvation and eternal peace. And then Father John
guided his Key to Heaven into my lock." 
"Is that a fact?" said the old nun even more evenly. 
"At first it hurt terribly, but Father John said the pathway to
salvation was often painful and that the glory of God would soon
swell my heart with ecstasy. And it did, it felt so good being saved." 
"That wicked old devil!" said the old nun. "He told me it was
Gabriel's Horn, and I've been blowing it for 40 years!"