slyly

adverb
1
in a secret or dishonest way, often intending to trick people
مکارانه, با حیله, حیله‌گرانه, موذیانه, فریب‌کارانه
synonym cunningly
2
in a way that suggests that you know something secret that other people do not know
مکارانه, موذیانه, حیله‌گرانه
He glanced at her slyly.
synonym knowingly(2)