beeswax

to mind one's own business. (Juvenile.) You just mind your own beeswax! Lay off! Mind your own beeswax!

Inf. none of someone's business. (Jocular.) It's none of your beeswax. I'm not telling. You'll never know. The answer is none of your beeswax.

an impolite way of saying that you do not want someone to know about your private life 'So where the heck have you been?' 'None of your beeswax!'

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.

A euphemism for “mind your own business.” Since “mind their own business” sounds harsh, if not impolite, the close-sounding word “beeswax” was substituted. Those to whom the remark was directed might still get their noses out of joint, but somewhat less so than if the word had been “business.” An interesting, although fanciful, piece of folk etymology tells us that American colonial women stood over a kettle and stirred wax to make candles. If they didn't pay attention, the wax or fire might burn their hair and clothing. Someone who let her concentration wander would be reminded to “mind your own beeswax.”