The manager was having difficulty with profits and fixed costs, so there was only one solution - more layoffs. But there were only two possibilities - Jack and Mary. This was going to be a hard decision - they were both excellent workers, and equally qualified - but one had to go. He was obviously going to have to interview them both and then decide.
So he called Mary in first. "I'm sorry," he began, "I've got some bad news. I'm going to have to lay you or Jack off."
She looked at him for a moment in silence then replied: "Well, can you jack off, I've got a terrible headache?"