Three turtles decided to have a cup of coffee. Just as they entered the cafe, it began to rain.
The biggest turtle said to the smallest one, "Go home and get the umbrella."
The little turtle replied, "I will, if you don't drink my coffee."
"We won't," the other two promised.
Two years later, the big turtle said to the middle turtle, "Well, I guess he isn't coming back, so we might as well drink his coffee."
Just then, a voice called from outside the door, "If you do, I won't go."