"Dad's wife is not his mother," I explained.
Zack said, "His mother is Grandma Leah."
"Right. And I am your mother, but I am not your wife."
Zack found this terribly amusing. "I know you're not my wife. If you were my wife, we'd sleep in the same bed together—or I'd sleep on the bottom bunk and you'd sleep on the top."
I got Zack to tell me what he understood from our conversation so far. "Dad's old wife is not my old mother," he said. "She never was my mother, even for a minute—right?"
A few months passed. I ran into my husband's ex-wife at a dinner party. She now lives with her third husband and her two sons from a second marriage. I told her Zack was considering her as a possible replacement for me. She laughed sympathetically and confided that she avoids talking to her two sons about her first marriage. "They have enough trouble dealing with me being married to someone who is not their father," she said.
Two weeks later Zack and I were exiting a local toy store when I saw that we were about to have a chance encounter with Zack's "ex-mother." Well, I thought, this is the moment. As we drew nearer, I whispered to Zack, "Here's somebody you've been wanting to meet."
"Don't say it, Suzanne," my husband's ex cautioned before I could make introductions. "Just don't do it." She attempted a warm greeting, but Zack shrank back against my legs.
Zack and I crossed the street to our car. "That was Dad's old wife, wasn't it," he said.
"Yes," I answered.
"Why didn't she want to talk to me?"
"That's an interesting question," I said. "I think maybe she was uncomfortable." Of course he asked why. "She thinks it's too hard for young children to understand about old wives and new wives," I explained.
Zack poured out his indignation at being underestimated. Finally there was silence. "You're the better mom," he said emphatically. It was a cheap victory, but I was past being picky.
Some years later Zack's dad and I divorced. Will there come a day when my son wonders whether a "new" mom or "new" dad is better? Definitely. He's a teenager now. But when I tell him the story of his worrying over choosing the better mom, he looks at me like I've lost my mind. "I never said that," he says.
More O on exes: Dealing with someone else's messy divorce