By the time the children turned four, Callum had become a familiar, if still carefully bounded, figure in their lives.

He came to birthdays when invited, attended an agreed preschool event, and learned that Oliver preferred building blocks to elaborate toys.

He had started therapy to confront the habits that had shaped his marriage and his relationships with both mothers of his children.

One afternoon he asked to speak after a school event.

We stood near the parking lot while the children ate snacks with Eva.

“Do you think,” he began, then stopped.