My ex-husband, now 40, cheated on me with a co-worker. I discovered the affair three years after it began, when we already had three very young children together. I immediately filed for divorce and he moved in with her. They fought for full custody, claiming their “two-parent household” was better, but they lost. Custody is shared 50/50. He married her before our divorce papers were finalized.

Things have remained hostile. She resented that I wished he would betray her too. He was angry that I told his family I had been tested for infections after learning of his affair. I only told them because they asked why I couldn’t be “friends for the kids’ sake.” I explained that before her, there was another co-worker I suspected he was involved with, and I wanted to protect myself. He called me petty and gross, insisting it was only one affair.
We use a co-parenting app for communication. I ignore his calls and texts, though face-to-face encounters are harder. I try to remain civil when the children are present, because I love them more than I hate him.
The kids are school-aged now and doing okay. They prefer my home and sometimes struggle at their dad’s. They see a therapist to help process everything. My ex and his wife were warned about pressuring the kids to call her “mom,” which they tried for a while. The children dislike her, and though I never say it aloud, I quietly celebrate that fact. I find her behavior appalling—helping destroy a marriage and then trying to claim my children as hers.
I never share these feelings with the kids, but they know there are issues between their parents. They also have some understanding that their father cheated, not because I told them, but because of his clumsy explanations. He doesn’t believe in therapy, so there was no professional support for him.
Around Halloween, my ex and his wife approached me at a school event. He said we needed to talk. I told him unless it was about the kids, we didn’t. Later, they cornered me privately. They revealed she is infertile and cannot have biological children. They asked me to be kinder, more encouraging, and help her bond with the kids so she wouldn’t feel like an outsider. He said her infertility was painful and that I had “successfully stopped” their bonding.
I asked why they were telling me personal matters that had nothing to do with me. He went from pleading to furious, calling my response disgusting and saying I should have at least offered sympathy. I walked away, unwilling to argue where the children might overhear.
That night, he sent multiple texts accusing me of insensitivity. He even tried to raise it at a school meeting. I ignored him and forwarded the messages to my attorney.
I thought this would blow over, but it hasn’t. That’s why I’m asking—was my response wrong?