The Fables aren’t used for the purpose of the morals, the point of the fables is their short length. I think I read somewhere that those morals were added years later just like the French fairy tale morals were.
Start with a sentence/paragraph at a time and just ask him to tell you what you read. After he responds, read the next sentence/paragraph. Be involved with an interested face. Don’t go all fact hunting on him. 😉 That might make him freeze because he’ll be afraid that he’ll get it wrong. Read one aloud and model the type of narration you want. Do it with him. Let him use animals to act out the story with. Let him draw a picture and tell you about it. You can do this with any lesson.
Remember that although this hard at first, narration is THE underlining method to all CM lessons. It is far better to persevere through them now and master it at this age than try to do it when he is 12.