I love Tween. I would do anything for him. Including, for one night a year, meeting up with his Dad, and pretending to have a good time.
It was Tween's birthday on Monday. He is twelve. I was encouraging him to have a party with his friends, but no - he wanted to go out for a meal and then to the cinema. Tween, Teen, Dad and me.
The happy fractured family.
To say this depressed me somewhat is an understatement. My last meeting with Tween's father involved him telling me that he wasn't going to let me see my kids over Christmas, for spite's sake. He underpays his child maintenance. He refuses to get involved in any school-related activity.
His girlfriend ate the birthday cake that I made last month for Teen.
So you can appreciate perhaps that spending an evening with this guy would not be top of my list.
But of course, you can't say no. And it is just one night. So, with a fixed smile - more of a grimace - I said I would like nothing better in the world.
I arrived at Tween's chosen eaterie to be greeted by a sulky Teen, a snotty ex husband and a Tween who looked like he was on acid. His eyes were shining and like dinner plates, and he had a huge smile on his face, bigger than I had seen for a long time.
He was just so happy that we were sitting together - just sitting, as a group, and talking - that it was hard not to let some of his positivity rub off. And so I was polite to my ex, as he was to me, and even Teen stopped sulking when he saw his huge hot chocolate advancing towards him. We talked about school and about The Hunger Games and Christmas (leaving aside my ex's previous ridiculous words) and even jokes.
During the short walk to the cinema, Tween bounced around between us, excited and moony. And in the cinema, with the ex and I book-ending the boys, he looked content. It was a look that I hadn't seen for a long time, bearing in mind the hard time he's had slotting into Secondary school.
It made me feel sad, and guilty. I had wrecked the structure of this family. Despite my efforts, I cannot fulfil the role of a man, and similarly my ex cannot be me. I saw for the first time how my children miss us being a united front.
It has made me think. But there is nothing I can do to mend it.