Husband and wife decide to sign up for a job at MI5, they go to the recruiting place and the person responsible for recruting tells the Husband.
"We need to be sure that you can be comitted at all times, your wife is in that room, heres a gun, I want you to go in and shoot your wife"
the man thinks for a while but shakes his head and says he simply can't do it.
Then it's the wife's turn, the man says to her "your husband is in that room, I want you to prove you're comitted by going in there and shooting him with this gun"
So the wife says ok and goes in the room, shutting the door, the man hears several banging noises, after quite a while the wife is still in the room and the man is getting concerned, then the wife comes out of the room and says...
"You bastard! you didn't tell me this gun was loaded with blanks,
I had to beat the bastard to death"