SERVE ONE RIGHT

{v. phr.} To be what (someone) really deserves as a punishment; be a fair exchange for what (someone) has done or said or failed to do or say. * /He failed his exam; it served him right because he had not studied./ * /Bob said it served Sally right when she cut her finger; she had taken his knife without asking him./ Compare: ASK FOR, HAVE IT COMING.