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
Heaven	HEV-ən	English (Modern)
Glover	['glʌvə]
Curt	[kə:t]
Iael	-	Biblical Greek
Seppo (1)	SEP-po (Finnish)	Finnish, Finnish Mythology
Chuldah	-	Biblical Hebrew