くちがへらない
fast-talking; always having another argument ready; not able to keep one's mouth shut; never at a loss for words
Also written 口がへらない
Expression, Prenominal
ああ言いえば、こう言いう。まったく、口くちが減へらない奴やつだ。
Whatever I say, he has a comeback ready. You can't get a word in edgewise.