This is a well written story about the struggles and conflicts that can arise with the in-laws. It has the elements of a good narrative including a wily villain (the mother). It looks like there was something in the soup itself, an herb perhaps, that was influencing the son's behavior.
I talked to Promise about it, asking why she had to bring food from her house when I could cook, but he told me to overlook it because he didn’t want any problems with her.
Switching the soups was a great resolution to the problem, as it gave the son the will to stand up for himself and his wife.
I always had the suspicion something wasn't right but I couldn't speak up because even I didn't know his mom as that kind of person and they probably wouldn't have believed me at that time.