チャラつく

godan verb (-ku)

try to look cool; act flashy; show off

Slang term for making an effort to appear stylish, cool, or attractive, often with a slightly negative or mocking tone. Implies trying too hard to impress.

• あいつ、最さい近きんチャラついてるけど、何なにかあったのかな。

  That guy's been trying to look cool lately; I wonder if something happened.

• チャラつくだけじゃなくて、中なか身みも磨みがけよ。

  Don't just try to look flashy; work on your inner self too.