get one's undies in a bundle

Meanings:

• 1.

  United Statesinformalhumorousliteral
  • To have one's underwear gathered or twisted into a bundle, describing a physical and literal state.

• 2.

  United Statesidiomaticinformalhumorous
  • To become agitated, upset, or overly worried about a minor or trivial matter; to get worked up.