The ubiquitous reality show celebrity Katie Price hit back at critics of her parenting by saying 'It's none of your beeswax' (see article here). This expression is a humorous, or childish, variation of 'it's none of your business'. There are various theories put forward on internet sites about how the phrase is supposedly linked to the fact that beeswax was formerly used in cosmetics and slathered on women's faces, but, as Michael Quinion of World Wide Words says, this is not true. Jonathon Green in his Dictionary of Slang says it is a 20th-century expression that was first coined in the US.
The phrase does not appear as an entry in its own right or on the 'beeswax' page in the OED, although it is mentioned on the 'mind' page. The word beeswax alone appears in slang dictionaries as a mid-19th-century term for a bore. It usually appears as 'old beeswax'.