If you live in the Los Angeles area and your follow college sports, it is expected that you favor either UCLA or USC; there doesn't seem to be much room for neutrality. When I married Donna 27 years ago and we came back to L.A., I clearly was part of a UCLA family even though Donna had not attended either university. And as our kids grew up, they favored UCLA too.
But for some families, it isn't quite that clear cut. For, example, the banner below was seen recently on my morning walk. It appeared just about the time UCLA and USC were about to face each other in basketball and it reflects when a graduate of one of these great campuses marries a graduate of the other (or perhaps when they have children attending each of the schools).
Ah yes, a house divided. Luckily, that wouldn't happen in our family unless some year the L.A. Dodgers and Detroit Tigers were to meet in the World Series. Except. . .in the Fall of 2006 daughter Alicia became a graduate student at USC. I just assumed that it would have no impact on campus rivalries because she never was a college sports fan. But a while back, she was visiting while I was watching the annual USC-UCLA football game. She walked in early in the 1st quarter of the game, saw me in front of the TV and asked, "Who's winning?" I told her that USC was in the lead and she quickly responded, "Good!" What! My daughter a USC fan? I guess it should be expected but it was still a shock; I had just assumed that she would ignore this rivalry.
A final aside. I would have liked to take a picture of the other side of the banner but could not do so because of its position on the house. Why? Because on that side the USC colors are on top with UCLA below. Even in a house divided, it cannot look like one side or the other is "more favored."