to go sour
01
(of situations, moods, or relationships) to become unpleasant or unsuccessful
![to [go] sour definition and meaning](https://cdn.langeek.co/photo/41295/original/?type=jpeg "to [go] sour definition and meaning")
Idiom
例子
Unfortunately, their friendship started to go sour after a series of misunderstandings.
The collaboration between the two teams began to go sour due to conflicting interests.
02
(of food or drinks) to become unpleasant in taste or smell
Collocation例子
I left the milk out overnight, and it started to go sour.
Be sure to check the expiration date; yogurt can quickly go sour.
