primness

/ˈprɪmnəs/
noun
  1. The quality of being very proper, formal, and careful about one's behavior or appearance, often in an exaggerated way.
    • Despite the casual dress code, his primness led him to wear a tie and jacket every day.
    • Her primness made her seem unfriendly at the party, as she refused to laugh at any jokes.
    • The teacher's primness was evident in the way she always sat straight and never spoke out of turn.