我わが物もの顔がお

na-adjective, noun

acting like one owns the place; behaving as if one were the owner

Describes a person's arrogant, entitled attitude, often in a shared or public space. Used with ～のようだ, ～に振る舞う, or as a な-adjective modifying nouns like 態度 (attitude).

• 彼かれは会かい議ぎ室しつで我わが物もの顔がおに振ふる舞まっていた。

  He was acting like he owned the conference room.

• 新しん入いりのくせに我わが物もの顔がおで指し示じを出だすなんて、信しんじられない。

  I can't believe he's giving orders like he owns the place when he's just a newcomer.