wàng ēn fù yì

ungratefulness

bite the hands that feeds one

【解释】忘记别人对自己的好处，反而做出对不起别人的事。

过河拆桥

guò hé chāi qiáo

比喻达到目的后，就把帮助过自己的人一脚踢开。

1. kick down the ladder

2. drop one's benefactor as soon as his help is not required

@Shawky Nasr