Possible Clues:

• Crime motive, perhaps
• Wronged person's cry
• In anger, even get retribution
• It is said to be sweet to get one's own back
• It's sweet, it's said
• Say no emphatically, reversing malicious action
• Carrie's motivation
• Said to be sweet, even with Reg around
• Whodunit motive, maybe
• Tit for tat