Related Clues:

• Was a fink
• Wasn't discreet
• Spoiled the surprise
• "__ you so!"
• Gave away
• Was a snitch
• Broke the news
• Ratted (on)
• Was unable to keep a secret
• Emulated a rat
• Was a ratfink
• Didn't keep mum
• Gave the game away
• Notified
• "I ___ you so!"