年としがいもなく

expression, adverb

unbecoming to one's age; inappropriately for one's years

Used to describe behavior, actions, or attitudes that are not suitable for a person's age, often implying childishness or immaturity. Typically modifies verbs or adjectives.

• 彼かれは年としがいもなく、ゲームに夢む中ちゅうになっている。

  He is absorbed in video games, which is unbecoming to his age.

• 年としがいもなく派は手でな服ふくを着きてしまった。

  I ended up wearing flashy clothes that are inappropriate for my age.