keep (one's) lips sealed

To not say anything (about something); to keep (something) a secret. Please keep your lips sealed about our engagement, we aren't ready to tell everybody just yet.

Common Names:

Name	Pronounced	Usage
Charley	['tʃa:li]
Edytha	-	English (Rare)
Pippin (1)	-	Ancient Germanic
Idowu	-	Western African, Yoruba
MichÈLe	mee-SHEL	French
Benedict	['benədikt]