let the cat out of the bag

idiomPart ofbag

let the cat out of the bag — idiom

1. to tell people about something that was meant to be a secret, often by mistake.

1.idiom
Definition

to tell people about something that was meant to be a secret, often by mistake.

Example

Rohan let the cat out of the bag about the surprise party.

Don't let the cat out of the bag — the engagement is still a secret.