いい年としをして

expression

despite one's age; old enough to know better

Used to criticize or express surprise at someone's immature or inappropriate behavior, implying they should act more their age. Often followed by a negative comment.

See also: いい年して

• いい年としをして、そんなことで泣なくなよ。

  You're old enough to know better—don't cry over something like that.

• いい年としをして、まだ親おやに頼たよっている。

  Despite being old enough, he still depends on his parents.