Disagree with you 100%. "You sound like" is specifically addressing what he is saying, not calling him names. I think you are being completely unfair to me.
Feel free to ask a friend you trust to be honest with you whether I was unfair, and whether there's a material difference between saying someone is childish and saying they "sound like a child," telling them "don't be childish," and saying they "behave like a child."
