sneaky

Adjective (2)

1. marked by deception“achieved success in business only by underhand methods”Synonyms: underhandunderhanded
2. marked by quiet and caution and secrecy; taking pains to avoid being observed“a furtive manner”“a sneak attack”“stealthy footsteps”“a surreptitious glance at his watch”Synonyms: furtivesneak(a)stealthysurreptitious