Possible Clues:

• ''Don't make me laugh!''
• ''Puh-leeze!''
• ''Doubtful''
• "Yeah, right!"
• Sarcastic comeback
• ''That's hard to believe''
• 'Mm-hmm, ri-i-i-ight'
• 'Riiiight!'
• "Riiiight!"
• "Ri-i-i-ght"