In the Fable of "The Boy who cried Wolf", the townsfolk end up not believing the boy when there actually is a wolf because he lied about there being a wolf so many times, leading to the flock of sheep getting eaten.
Now, suppose the townsfolk stopped believing him way earlier, and the boy stopped crying wolf, even if there really is a wolf, because he knows the townfolk won't believe him anyway.
Is there a term/proverb that can be used to describe this boy? Maybe something from a different fable or a real world event?