In-law issues

Long story short, my husband installed a kitchen for my son-in-law’s parents. They had a disagreement about the bill because they thought he should throw in all the extra work they wanted for free. My husband walked out, later apologized and gave them what they wanted even though it meant he lost 4 days wages. They then went complaining (and not with the full story) to my son-in-law (Pat).

Pat knows what likely happened knowing both parents and is angry with his parents and embarrassed. I’m upset about them treating my husband this way, and I’m more upset they are then running him down to family. I feel bad for my son-in-law. It is keeping me awake at night thinking about it. How do I stop dwelling and spinning on something I have no control over?