Possible Clues:

• 'I'm telling you, that's who!'
• Bully's words of authority
• "It's my party and I want to"
• 'According to whom?' retort
• "According to whom?" retort
• 'I do, that's who!'
• Exasperated parent's retort
• "I'm the one declaring this!"
• 'I'm telling you!'
• Parent's snarky reply