Furtively

That man over there has been glancing at us furtively for a while, do you know him?

She was deadly pale and breathing fast, glancing furtively towards the bed as she fastened her mantle, to see if she had disturbed me.

Tom glanced furtively at Mary.

Tom looked around furtively.

Tom would furtively read Mary's diary while she was having a bath.

Tom furtively glanced at his watch.

And furtively Time looked him in the face and edged towards him fingering with his dripping fingers the hilt of his nimble sword.