My mother, a UCLA graduate, switched her allegiance on a dime the day I enrolled at USC. She and my father attended every Trojans home game from that day forward. Familial blood may be thicker than alumni water but not so, it seems, when it comes to spousal relations.

And I know about it all too well. My husband, Brad, and I, both divorced and not in the market for anyone who didn’t ooze quality, had engaged in a keyboard courtship. He was avid, while I was reluctant at best. I refused to meet him for months, having been single for six years and not the least bit interested in sharing anything with anyone ever again. But he said he was willing to wait however long it took for me to muster up the courage, and he would even manage to overlook the fact that my diploma was from USC because he (unfortunately) was a devoted Bruin.

Letters soared back and forth between us, and because we were both 50 and counting, once I caved and we came face to face we wasted no time before announcing the nuptials, even though we both knew football season could be an impediment to forever after.

We shopped for rings before our first cross-town rivalry contest, the battle that former UCLA football coach Red Sanders once stated is not a matter of life and death: “It’s more important than that!” he insisted.

We set our wedding date for April, long before we truly realized what would happen in the fall at kickoff. Whereas I pictured us reveling in teasing trash talk, curled up on the sofa, popcorn at the ready — maybe even buying tickets to the big game someday — I was soon to learn that the Los Angeles gridiron civil war was more than we’d bargained for and, in fact, would permeate the walls of our love nest.

Brad started it. The first year, I scurried to Trader Joe’s like a nurturing newlywed bride to gather fun football food for what promised to be the fulfillment of my dream: our enjoying the light banter of frivolous competition in front of the television on a sunny Southern California Saturday afternoon.

When I emerged from the market, shopping bags in hand, I realized the man I’d promised to honor (Had I remembered to tell the priest to omit the word “obey”?) had switched out my striking cardinal and gold USC license plate frames for the ones decorated in the pale baby blue of his alma mater — ugh, UCLA Bruins!

Two could play at this game. I plopped the bags on the back seat, hopped on the 405 Freeway and beelined to SC Trojan Town at South Coast Plaza — yes, Virginia, there really is a retail Santa Claus for the University of Spoiled Children.

I whipped out my husband’s Visa card and promptly placed every fanatical fan item I could carry on it. I toted two suitcase-size handled bags filled with cocktail napkins, plates, cups, a king-size blanket, T-shirts, sweatpants, pajamas, signs, streamers, pennants, socks, hats, jerseys and my personal favorite, because he pretends to have symptoms of a stroke every time he hears it, a refrigerator magnet that plays the Trojan fight song.

Fight on! In no time, I had racked up an unconscionable dollar amount of paraphernalia that was sure to bring the house down. Then there was the year when USC was favored by a margin wider than the Pacific Ocean, the year the man I thought I’d be sharing my life with chose to clean out the garage and not even watch one quarterback toss. That was the year I ate all the cardinal and gold M&Ms myself.

Shortly after standing at the altar before family and friends, when we attended a UCLA-USC basketball game outfitted in our respective school sweatshirts, we were observed by a group of boorish Bruins. “Aw man,” one of them said to my husband. “Couldn’t you have done better?”

Clearly, you can’t major in manners on the west side of town. To this day, whenever the big day arrives for the football game more crucial than the Super Bowl, I find myself sometimes rising above it all in the company of Brad’s fraternity bro and his wife, an ex-UCLA song girl.

Although outnumbered and having to sit next to a song girl, I handle it gracefully despite some tiresome enemy tirades on the topic of campus controversy, á la parents paying to get their progeny into USC.

I point out that it’s a feather in one’s cap to be able to graduate from such a prestigious university, while our Bruin guests argue that those parents threw away their money.

Twenty years into sacramental union, we’d like to think we have for the most part let it go, especially since neither team provides the stellar spectacle that they did in our glory days from 1969 to 1973.

But every time November rolls around, unfurled is the flag flying our schools’ colors: half cardinal and gold, half just boring blue and yellow. “A House Divided,” it proclaims for all the neighbors to see. So perhaps to gain the truly proper perspective, it’s time for us to arrange a ceremony during which we renew our sacred vows adding just one more to the list: For better or for worse, for richer or for poorer … and no matter who wins the game.

The author is a second-generation Los Angeles native who lives in Fallbrook, Calif. A graduate of USC, she is the author of essays and stories that have appeared in newspapers and magazines including the Los Angeles Times, Orange Coast Magazine and Newsweek for over two decades.

L.A. Affairs chronicles the search for romantic love in all its glorious expressions in the L.A. area, and we want to hear your true story. We pay $400 for a published essay. Email LAAffairs@latimes.com. You can find submission guidelines here. You can find past columns here.