by stealth

confidentially covertly stealthily surreptitiously

sub-rosa under cover unobserved

openly publicly

clandestinely secretly surreptitiously

furtively hush-hush in camera in holes and corners on the Q.T. on the quiet on the sly privately slyly stealthily sub-rosa under wraps undercover wildcat

candidly frankly honestly openly overtly publicly

behind closed doors behind someone's back clandestinely confidentially covertly furtively hush-hush in camera in confidence in holes and corners in secret in strict confidence insidiously intimately o obscurely on the Q.T.

clandestinely covertly furtively personally privately quietly stealthily surreptitiously

behind closed doors behind someone's back confidentially hush-hush in camera in confidence in holes and corners in secret in strict confidence insidiously intimately obscurely on the Q.T. on the quiet on the sly privily slyly sub-rosa under the table underhandedly unobserved

publicly

openly