it never rains but it pours
不幸不单单是一件事情，而是接二连三地发生。
口语·抱怨接连不幸
英文释义
to experience a series of unfortunate events or problems all at once
例句
First my car broke down, then I lost my keys—it never rains but it pours.
典故来源
源自英国多雨气候，指雨一旦下就成倾盆，比喻坏事接踵而至。