I wouldn't feel guilty about it. I think sometimes if they could actually hear themselves they would laugh, too. I'll laugh at something difficult child says and she'll get horribly upset. But when I repeat her words back to her, she'll sometimes laugh, too. Although she tries to hide it at first.
And you're right. I'm sure it helps to diffuse the situation much better than becoming angry. And, as you said, he's not getting the response he was going for.
