Flap (one's) jaws informal verb phrase
To blather or chatter; to talk aimlessly or meaninglessly.
He keeps flapping his jaws, which vexes me.
You mustn't flap your jaws on serious diplomatic occasions
Stop flapping your jaws and get on with your work!
To use, do, or say something so often that people become bored with it
To talk continuously about things that are silly or unimportant
To talk for a long time about unimportant things
1. Used as rhyming slang for the pipe
2. Used to indicate nonsensical or foolish talk
3. Used to indicate a situation in which a girl is on her period and wipes the toilet paper with a red spot that looks like a cherry ripe.
To talk constantly.
The verb "flap" should be conjugated according to its tense.
It was often said by a photographer when he would like small children to look at the camera and smile before he took a photo.
When the photographer said “watch the birdie”, all of us looked at the camera and smiled.