1. The act of talking out your ass - most likely to occur when intoxicated
2. Giving verbal agreement to do something, but not following through
3. Slang for: a lie
4. exaggerated or unrealistically magnified
Over drinks and dinner last night, my boyfriend "flapping cheeks" when he said he would mow the lawn the next afternoon. The next day, he forgot that he had "work" to catch up on and didn't have time.
Heap Big Chief Flapping Cheeks was a flatulent donkey who amused many people with his hind end.