tell tales out of school

• talk out of school

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tell tales out of school (third-person singular simple present tells tales out of school, present participle telling tales out of school, simple past and past participle told tales out of school)

1. (idiomatic) To reveal confidential or sensitive information; to gossip.
   • 1831 April 27, “Court of Aldermen”, in The Times, page 4:

     I see then we have both been at school. But did you never, when you were there, hear it said, "Tell no tales out of school?"

   • 1857, William Makepeace Thackeray, chapter 8, in The Virginians:

     Mr. Washington had seen the gentlemen of honour and fashion over their cups, and perhaps thought that all their sayings and doings were not precisely such as would tend to instruct or edify a young man on his entrance into life; but he wisely chose to tell no tales out of school.

   • 1871, Louisa May Alcott, chapter 11, in Little Men:

     [T]he boys laughed and nudged one another, for it was evident that some one told tales out of school, else how could he know of the existence of these inconvenient treasures.

   • 1884, Martha Finley, chapter 9, in Elsie at Nantucket:

     "But now maybe I'm telling tales out of school," he added, with a laugh. "I shouldn't like to get the little girl into trouble."

   • 1907, Lucy Maud Montgomery, Shorty Stories: 1907 to 1908, published 2008, A Millionaire's Proposal:

     "Don't blush, Katherine, I am sure Mr. Willoughby won't tell any tales out of school to your old Valleyfield friends."

   • 1997, Stephen King, Desperation, →ISBN, page 94:

     "He wound up in the emergency room three different times, twice in Connecticut and once down here. The first two were drug ODs. I'm not telling tales out of school, because all that's been reported—exhaustively—in the press."

   • 2004 April 5, Peter Bailey, TIME‎, archived from the original on 2012 August 19:

     Bush's former Treasury Secretary, Paul O'Neill, told tales out of school, prompting hot denials—and an investigation of whether he disclosed classified information.

• blab, gossip, squeal, talk out of turn

• kiss and tell

• “tell tales out of school”, in OneLook Dictionary Search.