none of business
none of someone's business
not of someone's concern. (A gentle rebuke.) Q: When are you going to leave for home? A: None of your business. How I managed to afford all this is none of your business.
none of your businessalso nobody's business
do not interest yourself in matters that do not involve you â€œThose children should never be left alone.â€ â€œDon't tell me what to do - it's none of your business.â€