I don’t have problems at family gatherings where a brother-in-law is an Utah fan or something.
Why?
1. My family is not dumb as rocks*, so they all attended BYU. Even if they didn’t, again they are not dumb as rock so they wouldn’t attended a different school.
2. None of my family members married any Utah fans, because see #1.
Why would you allow Utah fans into your family? Honest question. Cut them off. Don’t invite them to your house for Thanksgiving. Don’t talk to them. Get a divorce if you married an Utah fan or a person from an Utah family. It’s not too late.
*I am pretty dumb. Got into BYU though.