furtively Synonyms

surreptitiously on the sly secretively on the q.t. insidiously in confidence in camera hush-hush in a secretive manner stowaway discreetly conspiratorially collusively clandestinely behind someone's back on the qt on the quiet in your heart in a secret in a quiet way by stealth voyeuristically unobserved under cover thievishly undercover sneakingly sneakily shiftily on the side behind closed doors in secret privately poaching mysteriously latently intimately indirectly incognito furtive esoterically enigmatically deceitfully craftily covertly privily quietly sub-rosa backstage trickily