How Far ....... ?

How far can you trust a friend .......?

Mike left to go help in the Crusades and decided that his wife should wear a chastity belt (Steel underwear).

So he locks her up and gives the key to his best friend, Frank.
Mike, "If I'm not back in two years, unlock my wife and set her free to live a normal life."

So, Mike leaves on horseback and about a half hour later, he sees a cloud of dust behind him. He waits for it to come closer and sees Frank.

"What's wrong?" He asks.

Sipho replies. "You gave me the wrong key!"