Is this an old joke?
The Jesuit pulls out a cake and cuts it in two, one large piece and one small piece.
The Jesuit eats the large piece. The Franciscan eats the small piece and then says, "That was a bit rude."
The Jesuit says, "Why?"
The Franciscan says, "Because you took the large piece."
The Jesuit responds, "Well, if I hadn't taken the large piece, which piece would you have taken."
The Franciscan responded, "The small piece."
The Jesuit says, "Well, I don't you what you're complaining about. After all, you got the bit you wanted."