Related Clues:

• Emphatic assertion
• 'No joke!'
• Emphatic follow-up
• "All kidding aside"
• Order reinforcement
• Parental postscript
• Unequivocal statement
• 'Dead serious!'
• 'Seriously'
• "My mind is made up!"
• "For real!"
• Mayday Parade "I Swear This Time ___"
• "No joke!"
• 'Believe you me!'
• 'That's no kidding'