be on (one's) good behavior

To be very polite or exercising exceptionally good manners. Primarily heard in US. Now, you kids must be on your good behavior for your Auntie this weekend! Good morning, class. I hope everyone was on their good behavior for the substitute teacher yesterday.

Common Names:

Name	Pronounced	Usage
Ji-Hye	jee-hye	Korean
Oralee	-	English (Rare)
RisteÁRd	-	Irish
ŽIgmund	-	Slovak
Seraiah	-	Biblical, Biblical Hebrew
Nikon	-	Ancient Greek, Russian