Some of that needed to be between himself and Athena.

‘I like…swimming,’ Christa said. She’d pushed her shoes off-she hated shoes-and her feet were resting on Oscar. ‘I like…dog.’

‘I think Oscar likes you,’ Athena said.

‘Does this mean Christa is my sister?’ Nicky asked and Nikos’s thoughts went flying again. The issues were too big. Huge.

‘I guess she is,’ Athena said softly. ‘Your half-sister.’ Then she said gently, ‘Christa has something called Down’s syndrome. That means she was born with something a little different from most children. All the bits that start a baby growing…they’re called chromosomes. Christa got an extra one. It makes the tips of her ears a bit small. It makes her tongue a little bit big and her eyes really dark and pretty. And it affects her in other ways too, including her speech.’

‘But she likes Oscar.’

‘She does,’ Athena said gravely, smiling at Christa. ‘I think Christa is our friend already. I think having her as your sister might be really cool.’

So much for leading the conversation, Nikos thought. It was now about the three of them. He was right out of the equation.

Somewhere, once, he’d read some scathing comment on fatherhood. Mothers knew all about their children’s dramas, their love lives, the spots on the back of their necks. Fathers were vaguely aware there were short people in the house.

Not him, he thought. With Christa, he’d been so much more hands on. But he felt sidelined here.

‘I wanted a sister,’ Nicky was saying, cautious. ‘A little sister. But Christa’s nine.’

‘I’m nine,’ Christa said, nodding grave agreement.

‘But she’s much shorter than you,’ Thena said. ‘I think she always will be, so that means she’ll always be your little sister.’

‘So I get to look after her?’

‘If you want.’

‘Do I hafta share?’

‘I guess you and Christa can work those things out for yourselves,’ Athena said, and Christa looked at Nicky and beamed.