English

Verb

blow someone's cover

1. (idiomatic) To reveal that someone's behavior, situation, or identity has been fabricated or deliberately misrepresented for an ulterior motive.
   • 2007 Feb. 15, Andrew Marshall, "The Escape Artist," Time (retrieved 6 July 2015):

     Iskander's role as a G.A.M. operative was secret—until I unwittingly blew his cover that day.

   • 2014 Nov. 19, Katrin Bennhold, "A Tabloid ‘Fake Sheikh,’ Bane of Crooks and Royalty, Finds He’s Now the Story," New York Times (retrieved 6 July 2015):

     Others have tried to blow his cover: George Galloway, a left-wing British politician and supporter of the Palestinian cause, published Mr. Mahmood’s photo on his website in 2006 and accused Mr. Mahmood of disguising himself as an Arab businessman and trying to entice him to make anti-Semitic comments over lunch.

   • 2015 Aug. 24, Payton Guion, "Rachel Dolezal steps down as local NAACP president amid race controversy," Independent (UK) (retrieved 6 July 2015):

     [O]ne of her adopted brothers said that she had asked him not to reveal that she is white. "She took me aside and just told me not to blow her cover," Ezra Dolezal, one of her African American adopted siblings, told KREM-TV.

2. (reflexive, idiomatic) To reveal that one has fabricated or deliberately misrepresented one's own behavior, situation, or identity for an ulterior motive.
   • 1984 Aug. 24, Lawrence Van Gelder, "The Jigsaw Man (1984): Review Summary," New York Times (retrieved 6 July 2015):

     This spy film purports to be inspired by the true story of Kim Philby (1912-1988), a British intelligence officer and Soviet spy during the 1940s and '50s who gained international notoriety when he blew his cover and defected to the USSR in 1963.