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.

[TahlilGaran] English Idioms Dictionary ▲