I just remembered the punchline to an old joke.

"Why is your organ so small?"
"I didn't know I was going to be playing in a cathedral."

or the variation of a man comparing the size of his wife's ass to a gas gril:

"You think I'm gonna fire this up for that little weiner?"

__________________
"Even a man who is pure of heart
And says his prayers by night
Can become a wolf when the wolfbane blooms
And the moon is full and bright."