If anything sours the relationship, it is likely to be real differences in their world-views.

假如有什么事情使关系恶化的话，那可能就是他们在世界观方面所存在的实质性差异。

The cream sours in hot weather.

奶油在热天会变酸。

Milk sours quickly in warm weather.

牛奶在温暖的天气下会很快变质。

Sea air sours it, I heard.

我听说海风会使啤酒变酸的。

Sours sweeten under certain conditions.

在一定的条件下酸的东西可以变甜。