none of (one's) business

Something that is of no concern to another. It's really none of his business what I do with the money I earn.

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.

(It's) none of your business!

It is nothing that you need to know. It is none of your concern. (Not very polite.) Alice: How much does a little diamond like that cost? Mary: None of your business! John: Do you want to go out with me Friday night? Mary: Sorry, I don't think so. John: Well, what are you doing then? Mary: None of your business!

none of one's business

Not one's concern, as in How much I earn is none of your business. This expression employs business in the sense of "one's affairs," a usage dating from about 1600. (Also see mind one's own business.) A slangy, jocular variant from about 1930 is none of one's beeswax. The related verb phrase have no business is used to indicate that one should not meddle or interfere, as in He has no business discussing the will with outsiders.