come clean come clean /kʌm kliːn/

verb

1. [Informal] Admit or acknowledge a wrongdoing or error  ( fess up [Informal] , make a clean breast of , own up , come clean [Informal] , cop to [Informal, N. American] )
   admit or acknowledge a wrongdoing or error
    The writer of the anonymous letter owned up after they identified his handwriting
   the writer of the anonymous letter owned up after they identified his handwriting