Never tell the devil where your goat is tied

Meaning

This serves as a warning not to share your plans or vulnerabilities with people who do not have your best interests at heart. It suggests that if you are careless with your secrets, someone will inevitably use that information to sabotage you.

Folksy, cautionary

Used in a sentence

• I would not tell your boss about that job offer until you have the contract signed, never tell the devil where your goat is tied.
• You should keep your bank login to yourself because never tell the devil where your goat is tied.
• Why are you bragging about your secret recipe to the neighbors, never tell the devil where your goat is tied.