The act of looking out suddenly, as from behind a screen, so as to startle someone (as by children in play), or of looking out and drawing suddenly back, as if frightened.
1606, King Lear by ,That such a king should play bo-peep, And go the fools among.
1881, Geneva Gazette - Jul 8, 1881, page 2, "Official Paper Of The Village"They have not employed spies, nor been voluntary or involuntary witnesses of misdeeds or played "bopeep" through key-holes or from step-ladders through transom windows, upon the privacy of their political adversaries.