What (you) don't know won't hurt (you).

something that you say which means that if you do not know about a fact or a problem, you do not worry about it.

'Tell me how much you spent on the car, then.' 'No, what you don't know won't hurt you.'

• wring something out of
• wring something out of someone
• wring your hands
• write in
• write in something
• write off
• write off something
• write on the back of a postage stamp
• write someone off
• write something off
• write something on the back of a postage stamp
• write up
• write up something
• writing is on the wall
• writing on the wall
• writ large
• written all over face
• written all over your face
• written in the stars
• wrong side of the tracks
• yank chain
• yank someone's chain
• year after year
• year by year
• year in, year out