hugger-mugger

adj. secret, clandestine. v. to keep secret, conceal

(from DICTIONARY. COM)

That was supposed to be huggermugger, you lil' bugger!
Hey Johnny, let's keep this little thing between you and me. Y'know, real huggermugger.
I can't tell you where the missiles are located. I'm afraid that information is strictly huggermugger.
Blimey! Uncle Moishe huggermuggered the crumpets 'gain!
If you knew, then it wouldn't be huggermugger anymore, WOULD IT?!!?
You are the WORST huggermuggerer I've met in my life.
Rodriguo could no longer huggermugger his feelings for Cynthia.
His pally-wally was too chubby-wubby to huggermugger under the ruggy-tuggy.