We have season tickets and one of the families near us has a couple kids who would come over to visit their family and then rudely squeeze in with them on the bench. There were others sitting next to them, who were suddenly pushed out of their paid for seats, or who barely fit on the bench because they had the bad misfortune of sitting next to an entitled family. Eventually, the BYU stadium rep would have to come ask them to go back to their seats, which then made it awkward for everyone around them. Sit in the seats you paid for.