Like all interfaith couples, we’ve had to make room for each other’s traditions. Ground rules have helped. My husband, for instance, is prohibited from scribbling profanities across my signed Derek Jeter ball. Likewise, I understand that if I wear my Mariano Rivera jersey into the bleachers at Fenway, I’m on my own.

For 10 seasons of marriage — 192 regular series games, three ALCS, and three world championships — we’ve made it. But in the last few years something has grown between us, threatening the uneasy stability of our alliance. Of course, I’m talking about our very own bambino.

He arrived just in time for the season opener in 2007. When the Sox and Yankees played each other a few weeks later, we watched our first game as a family, with the bambino sacked out across my lap. At first, we were too tired for trash-talking, too baby-drunk to engage in any rivalry. As new parents, we were finally playing on the same team. Until the gift boxes arrived. Red Sox bibs and burp cloths. Yankees sippy cups. Stroller blankets. We laughed as the swag piled up around the apartment. We put a Red Sox booty on his left foot, a Yankees booty on his right, and admired our tiny mixed-up baseball fan.

Then my husband left for work and I replaced the Red Sox booty with the Yankees one. Next I started dressing him in Yankees onesies. And taking pictures. And posting them on Facebook. And so it began, the guerrilla war for the heart and soul of our child. My husband trained the bambino to clap whenever he heard the words “Red Sox.” I responded by tacking a Yankees pennant above his changing table. My husband’s crowning achievement: teaching him to call them the “Yuckies.”

Barely, we avoided couples counseling. We spent weeks lobbying each other to give in, calling up old childhood memories, recounting tales of fan devotion. We tried begging. Then bribery. Still, neither of us would budge.

You expect marriage to require compromise. You get used to each other’s style of mashed potatoes at Thanksgiving; you tolerate old jazz records when you’d rather listen to Springsteen. But you never expect to surrender something that feels like an essential part of yourself. Unfortunately, that’s what one of us was facing. So we made the only choice we could. We boxed up the paraphernalia, stopped our campaigns, and agreed to let our son decide for himself.

These days, he scampers around the playground sporting a Red Sox visor and a Yankees shirt. When asked, he says he likes both teams. The bambino turned 5-year-old boy is oblivious to the contradiction. He doesn’t know what it means to play a one-game playoff or to come back from a three-game deficit to take the series. He knows nothing about bloody socks or blown saves or home runs that come so late in the night that they actually happen the following morning. He has yet to experience a heroic victory or, for that matter, a miserable defeat.

But before we know it, the slight shiver of October will be in the air and he’ll be begging us to let him stay up past his bedtime. He’ll hover inches from the TV, rally cap on, praying, pleading, for one last hit. In that moment, as he holds his breath and waits for the payoff pitch, he’ll understand that a person can truly love only one team.

My husband and I will have to wait until that day to find out which team it will be. At least we agree on one thing: It better not be the Mets.

Erin Blakeley is a freelance writer and mother of two. Send comments to connections@globe.com. TELL YOUR STORY. E-mail your 650-word essay on a relationship to connections@globe.com.