ちゃっかり

adverb, adverb taking the 'to' particle, noun or participle which takes 'suru'

shrewdly; smartly; calculatingly

Describes acting in a clever, self-serving way without appearing pushy; often implies quietly taking advantage of a situation. Used with と or as a する-verb.

• 彼かれはちゃっかりと一いち番ばんいい席せきを取とった。

  He shrewdly took the best seat.