Why does Nezha, the leader of Shi Gandang, always call Shi Gandang an old thief?

when Nezha became a god, he was still a minor. Shi Gandang was older than him. When he first met him, he thought he was a demon, so he was called an "old thief".

You read it very carefully. I have read it a little. I suspect that the screenwriter and the sequel to Journey to the West are the same person. I gave up decisively. Both of them have Qiaojiazhuang and Shine, and they are reincarnated. All of them are gods in the sky pretending to be demons, and all of them have an emissary pretending to be a "second brother" as undercover. ......