It’s a lesson that most people who get married have to learn at one point or another: a marriage doesn’t just permanently link you to a person, but often their family as well. While some find it controversial to prioritize a partner over close family members, the reality is that it is usually necessary if your relationship is serious enough. Ultimately, the person who has the most say in how you build your life is the one you choose to build it with.
This isn’t to say that family shouldn’t be listened to and supported when it feels right, but some people have a very skewed perspective of when that is appropriate. It can lead people to do things that are disrespectful to their partner just because they want to please their parents or other relatives. It is an unfortunate situation, but not an uncommon reason for tension between a couple.