口くちを叩たたく

expression, godan verb (-ku)

speak brazenly; talk too much; never shut up

Used for someone who talks impudently, thoughtlessly, or excessively, often in a way that annoys others. The phrase carries a negative, critical tone.

• 彼かれはいつも口くちを叩たたいてばかりで、人ひとの話はなしを聞きかない。

  He's always running his mouth and never listens to others.

• あの政せい治じ家かはまた口くちを叩たたいて、失しつ言げんした。

  That politician shot his mouth off again and made a gaffe.