Conversation breakers from kids

How do you stop another person from parrotting everything you say? The tried and true method was to say the person is “a silly duffer.” Of course, they can’t parrot this or they’ll be admitting it. It’s foolproof. Or it was… 

Me:
“Daniel’s a silly duffer!”
Daniel:
“Daniel’s a silly duffer!” *pause* “Ha ha! I called you Daniel!”

Now what about those neverending yes/no debates. How to diffuse them without the tears? Impossible you say? Emma knows the way.

Daniel:
“Yes!”
Emma:
“No!”
Daniel:
“Yes!”
Emma:
“No!”
Daniel:
“You’re lying!”
Emma:
*pause* “No, I’m Emma.”

Can’t beat that, can you?