So on a Saturday morning in the living room on Vernon Street, Luca Aldarossi sat in the armchair and I sat on the couch and our children sat between us on the rug, and we told them that we were not going to be married anymore.

Sam was six.

He said, “Okay,” and then, about four seconds later, “Is it because I broke the thing in the car?”

He meant a plastic vent clip he had snapped off two weeks earlier and had, apparently, been carrying around ever since.

I have never in my life had to work harder to keep my face level.

“It is not because of the vent,” I said.

“It is not because of anything either of you did or said or thought.