"Only I get to tell my awful kid that it is awful. How dare you try to teach my kid manners" - the dad, probably. Honestly, I hate parent who never let anyone correct their child. Especially when they let them do everything they want. Kids need to know their borders too.

I would file a noise complaint.

Turn it around on him. I would have said exactly this, "well if you were being a parent and actually told your kid what to do, I wouldn't have to do your job. Have the common courtesy to realize he's being unnecessarily loud and not everyone wants to hear your hell spawn."

Tell him to stop being a little bitch and take control of his kids before they take control of him