There is this wall between Heaven and Hell, which is cared for in alternate aeons by the two sides. However it has fallen into disrepair, prompting St. Peter to seek out Lucifer.
"Hey Lou, it's your turn to fix the fence. The Boss says it looks awful. Get it done," intoned the old man.
"I don't care how it looks," says Lucifer, "I'm not doing anything."
"You have to," says St. Peter, "It's your official obligation. We have a contract to that effect. You're committed."
"I don't give a damn about any contract," replies Lucifer, "As you should know by now, I don't care what it says - I'm not going to do anything."
"You have to," insists St. Peter, "The law is the law. If you force us to, we'll have to sue you."
"Sue me?" cries Lucifer, breaking into his famous nasty laugh, "And where are you gonna get a lawyer?"