I love this! He might have to save it for appreciate audiences and avoid using it around his teacher? Alternatively, this may be an opportunity for beginning to teach self-advocacy.
He might be interested in how languages evolve? You could illustrate how what was proper language use in the past is confusing now. He might pick up some other words or phrases though. 😂
He might benefit from learning about how good communicators and authors modify their language for their audience. I don't recall if this is age appropriate, but "Mother Tongue" by Amy Tan discusses the topic of how ordinary people speak different versions of English depending on their audience or environment.
