sneakiness

/ˈsniːkinəs/
noun
  1. The quality or behavior of being secretive, dishonest, or sly in order to avoid being noticed or to get what you want.
    • The sneakiness of the plan made everyone suspicious.
    • Her sneakiness helped her avoid chores, but it annoyed her parents.
    • I don't trust his sneakiness; he always hides what he's doing.