When a new romantic relationship forms, relationships also tend to form between the two families. But not everyone is going to get along.
If your boyfriend and sister are fighting over insignificant things like who gets the remote or where to eat for dinner, then they have formed their own brother and sister relationship. This should not be a big deal if they don’t mean it. However, if they take personal jabs at one another and the fighting is affecting everybody else, then something needs to change. But it’s not your job to change it. They need to work things out for themselves and not put you in the middle. If this is someone who will be in your life forever, then your sister will have to put her pride aside and accept it. Likewise, your boyfriend will have to accept that your sister is one of the most important people in your life. They will need to come to a compromise and find a solution on their own.
The best thing you can do is express how you’re feeling to both of them, and then step out of the ring to let them duke it out.
