mad muggin'
A smug face made with a sneer and a smirk, usually for teasing someone you like; it's like giving them the finger with your face.
Your coworker told a joke about your boss and you gave them the mad muggin’ in the middle of a meeting.
Your best friend said you had a weird hair day and you gave them the mad muggin’ during lunch.
Your buddy said your video game skills were trash and you gave them the mad muggin’ while playing.