You searched for: “aliud corde premunt”
Aliud corde premunt, aliud ore promunt.
One thing they conceal in the heart, they disclose another with the mouth.

Another version is, "No use trying to keep a secret." A warning that when more than one person knows something, it is no longer a secret because there is usually someone who will talk about it.

This entry is located in the following units: ali- (page 1) cor-, cord-, cour- (page 1) Latin Proverbs, Mottoes, Phrases, and Words: Group A (page 13)