But how? All the possibilities crashed into one another as they jostled for position. Was Dad married to Grace before he married Mum? Was that it? But if that was right how come they’d never told me, especially if I had half-siblings? There was no shame in being divorced. The parents of almost everyone I knew had divorced and remarried. Why wouldn’t Mum and Dad have mentioned it?

Then it hit me. Clio was almost exactly the same age as me. We’d laughed at the coincidence of it all. But if we shared a father, then that could only mean one thing, surely? Dad must have been sleeping with Mum and Grace at the same time.

I could see on Grace’s face the moment when she realised that I had worked out the truth. Dad had been having an affair with Grace whilst he was married to Mum.

But no, that wasn’t it. There was something more. Grace looked as if her entire world had just collapsed in on itself, as if just standing there was as much as she could manage. An affair was crappy but it didn’t merit such an extreme response, especially not over thirty years later.

Hector, who had stalked away to think through what he had just learnt, now strode back to us.

‘So, Dad was married before?’ he asked. His mind was clearly following the same path as mine, and I could see him scrutinising me, searching for clues to my age. His eyes flitted to Poppy and Noah as if they could be the solution to the conundrum, but when he looked back at me confusion was still etched across his face. He looked so much like Dad, I could see that now. Except that I rarely saw Dad when he wasn’t smiling or laughing at some joke or other. Hector’s face seemed set in a perpetual scowl.

Grace shook her head sadly.

‘Then he was having an affair?’ asked Hector, his tone slightly softer now. ‘Was Dad having an affair? Is that it? Why did you never say? How long have you known? Oh, Mother.’

For God’s sake! Did he really call his mum ‘Mother’? What an idiot he was! How could Clio and Mrs Newman or Grace or whatever she was called, how could they be so lovely and this man, my so-called half-brother, be such a moron?

‘I’m afraid,’ said Grace quietly, ‘that that’s not quite it.’ She turned to where Clio was standing with Noah. ‘Clio!’ she shouted.

Clio looked up from her examination of Noah’s patterns.

‘Could you come here just for a moment, please?’

‘I’ll be right back,’ Clio said to Noah, tapping him gently on his head as she returned to the group. Poppy hung back with Noah.

‘There is something that I have to tell all three of you,’ Grace said.