拴在一条线上的蚂蚱 - Chinese Idiom

拴在一条线上的蚂蚱

Literally means:

grasshoppers tied to one thread

Actually means:

neither can get away

蚂蚱 (grasshopper) is a colloquial name for locust, i.e. a type of insects that can hop and fly. The phrase refers to two grasshoppers tied to one thread, and if one moves, the other has to move too.

It metaphorically means two persons get entangled with each other, and neither can act independently without the other. In other words, they have to take actions together. It often indicates when taking risks or doing something evil, the two must act together, or fall together in times of bad luck. Derogatory.

蚂蚱，蝗虫的俗称，会跳会飞的昆虫。拴在一条线上的蚂蚱，被一根线拴住的两个蚂蚱，一个动了，另一个也得跟着动。

比喻两个人牵扯在一起，必须共同行动，谁都无法撇开对方单独行动。多指做有风险的事，甚至做坏事时，两人必须共同参与，或者碰到倒霉的事，两个人一起倒霉。具有贬义色彩。