open (one's) big mouth

(redirected from opens their big mouth)
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open (one's) big mouth

To say something that is meant to be a secret; to say something in an indiscreet, noisy, or boorish manner. Why did you have to open your big mouth about my crush on Tommy? Why couldn't you just keep it between us? We would have gotten away with the plan if she hadn't opened her big mouth!
See also: big, mouth, open
References in periodicals archive ?
But in soapland, a marriage ceremony often descends into carnage, either because someone opens their big mouth during that bit where the vicar asks about ``lawful impediments'', or because a late arrival causes all hell to break loose (see Emmerdale's Dawn and Terry's nuptials this week for details).