box clever
To act skillfully and cunningly or deceitfully to achieve a desired outcome. Primarily heard in UK. The principal is already on to you, so you're going to have to box clever to avoid a suspension.
box clever
act so as to outwit someone. British informal 1950 Alexander Baron There's No Home If you box clever and keep your mouth shut…you ought to be able to count on a suspended sentence.
box ˈclever
(British English, informal) act in a clever way to get what you want, sometimes tricking and deceiving somebody: Suzie realized that she had to box clever. She had to let Adam think she trusted him.