What if the brother-in-law is rude to his brother and daughter-in-law?

In this case, the best way is to ask your brother-in-law to apologize to his wife, so that your sister will feel much better. If your brother-in-law refuses to apologize to your sister, you can go to your sister's house and ask her to talk to your brother-in-law. You can also go to your brother-in-law's house and ask him to apologize to your sister, so that your sister will feel better and they will not quarrel over this matter. You can also go to their house and ask him to apologize to your sister, so that your sister and your brother-in-law will be very happy. If neither your sister nor your brother-in-law will apologize to your sister, you can ask them both to apologize to you. You can ask them to apologize to your sister, and then you can ask them to apologize to your brother-in-law. You can also go to their house and ask them to apologize to your sister.