During the crusades, young men were expected to join the military and fight.
One young man had just gotten married and was forced to leave before consummating the relationship. She was still wearing her chastity belt and he had the only key.
Concerned about her well being, he met with his best friend who was staying behind. He told his friend, “Keep this key, and if I am killed, you have my blessing to use it. Promise me that you will be an honorable friend and take care of her, and that you will not use it until you have confirmed my death.”
The two men made a pact, and the young man rode off to join the distant battle.
About two hours later, as he was traveling to join the battle, the young man noticed a rider approaching at a full gallop, with a cloud of dust behind him. It was his best friend.
As his friend approached he was waving frantically, with the key in his hand shouting at the top of his voice, “You gave me the wrong key!”