go sour

v. 变酸, 出漏子, 不再受欢迎

例句与用法：

Their relationship soon went sour.

他们的关系不久就变坏了。

If you keep the milk in the refrigerator, it won't go sour so quickly.

如果把牛奶保存在冰箱里，它不会那么快就变酸。

详细释义：

令人失望

After a promising start, things began to go sour.

起先是很有希望的, 后来却开始变得让人扫兴。