throw someone a curve

/TH R OW1 S AH0 M W AH0 N AH0 K ER0 V/
verb
  1. 1

    To surprise; to introduce something unexpected or requiring a quick reaction or correction.

    โ€œHe really threw me a curve when he asked me a personal question at work.โ€

Source: https://en.wiktionary.org/wiki/throw%20someone%20a%20curve