1 definition by TipsFromTheHelpDesk
When you've just told someone something they don't appreciate (e.g. insulted them, their family, or anything else in general) and they're getting all exasperated, and are trying to think of something to yell at you, but their brains aren't as quick as their mouth, so their lips start moving around just gettin' ready for the words with their facial expression still shocked.
So, I called her a dumbass, and I was doing really well at keeping my laughter in check, until she started lip flappin'.
by TipsFromTheHelpDesk September 5, 2017