心ㄒㄧㄣxīn口ㄎㄡˇkǒu不ㄅㄨˋbù一ㄧyī

  1. 心裡想的和嘴裡說的不一樣。形容為人虛偽。《醒世姻緣傳·第八二回》：「我是這們個直性子，希罕就說希罕，不是這們心口不一的。」似口是心非

英heart and mouth at variance (idiom)​; keeping one's real intentions to oneself, saying one thing but meaning sth different
德heucheln (V)​