One of those "someone pisses off someone/something and unrelated people get cursed but it's a funny curse" gags but it's Lucifer, Mephistopheles and Barbatos getting cursed so they can't ever say Diavolo's name without messing it up somehow.
They're all in a meeting together and Barb is serving Dia some tea and he's like "here Lord Diabolo. Diabolo? Dialovo??"
And Lucifer and Mephisto are super confused but when they try to say his name they mess it up even worse. Eventually they can't say "young master" or "your majesty" either so they're all like "here's the paperwork, The Guy I Work For"
















