reticent, taciturn, tight-lipped, furtive, undercover, with bated breath, in private, in the dark, in chambers, by a side door, under the breath, in the background, between ourselves, in privacy, in a corner, under the cloak of, reserved.
"secretive." YourDictionary, n.d. Web. 17 August 2018. <http://thesaurus.yourdictionary.com/secretive>.
secretive. (n.d.). Retrieved August 17th, 2018, from http://thesaurus.yourdictionary.com/secretive