树倒猢狲散 When the tree falls, the monkeys scatter. When a powerful person falls, those who leaned on him leave. In Dream of the Red Chamber, Qin Keqing warns Wang Xifeng that the family might one day prove the saying true.
势利眼 Power and profit eyes. Deciding how close to be by the other person’s wealth and power.
有奶便是娘 Whoever has milk is mother. Siding with whoever offers an advantage.
过河拆桥 To cross the river and pull down the bridge. To drop those who helped once the goal is reached.
前倨后恭 Arrogant before, respectful after. From the story of Su Qin, whose sister-in-law treated him with contempt while he was poor and bowed to him once he was powerful.