The boss had to fire somebody, and he narrowed it down to one of two people: Mary or Jack.
It was an impossible decision because they were both decent workers. Rather than flip a coin, he decided he would fire the first one who used the water cooler the next morning.
Mary came in the next morning with a horrible hangover after partying all night. She went to the cooler to take an aspirin. The boss approached her and said, "Mary, I've never done this before, but I have to lay you or Jack off."
"Could you jack off?" she said. "I feel like shit this morning."