口蜜腹剑------A honey tongue, a heart of gall

例句：

A: He often apple-polishes me and I'm flattered.
他经常奉承我,让我感到受宠若惊。
B: Be carefkul! A honey tongae, a heart of gall.
小心！ 口蜜腹剑。

同义词：

1.be nasty-nice

2.Bees that have honey in their mouths have stings in their tails.