Katie was numb with shock. ‘Are you telling me that all this time, you and Dad have just been pretending to be happy for our sake?’

Sophie shook her head. ‘Not at all. You’re the reason why we stayed together at first. But we were both committed to fixing the damage and we worked hard to save our marriage. Eventually we found a way through it and found each other again, as cheesy as that sounds. I can honestly say, hand on heart, that we’ve been very happily married for the past ten years, Katie. It’s important to me that you know that.’

Her dad, her lovely, reliable, trustworthy dad, had an affair with the neighbour? Katie tried to remember Angie. She had a hazy memory of a glamorous looking woman but it was the exotic scent of her perfume that she remembered the most. She could almost smell it now.

‘Oh, Mum,’ she said. ‘I can’t believe it. I had no idea that any of this had happened.’

‘Well, you were too young. Dad and I tried our best to keep things as normal as possible. He stayed at home, with us. We stuck together. But living next door to Angie was too hard. I couldn’t escape it; it was like torture. After a few months we decided to sell up and move to Cambridge for a new start. It was the right decision for us.’

‘How could you forgive Dad though?’ Katie genuinely couldn’t understand how she could get past a betrayal like that.

‘Marriage is hard, Katie. Real life isn’t a fairy tale, you know, human beings are imperfect, we all make mistakes. But I had a choice, did I let your father’s indiscretion destroy ten years of a happy marriage and break the home we’d created for you and Tom, or did I forgive him? I knew I had to at least try and so I did. I’m not saying it was easy but we got there in the end.’

‘But how could you trust him?’

Her mother smiled at her. ‘I don’t know really. Of course I didn’t at first, it takes a long time to rebuild trust once it’s been broken like that but I knew deep down that he was still the wonderful, kind and thoughtful man that I loved. He just made a mistake.’

Katie couldn’t decide if her mother was the saintliest person in the world or the stupidest. ‘Does Tom know?’

‘No, he doesn’t.’

Katie thought back over her childhood, seeing it with a fresh pair of eyes. It had been a happy one, she thought. Surely that wasn’t an illusion. There had never been any hint of animosity or resentment between her mum and dad. They had just been normal parents – happier than most normal parents, in fact. How had her mother hidden this secret for so long?

‘Well, it seems Freddy knows all about it,’ she told her.

‘I don’t know how he knows. He was the same age as you when it all happened. What’s he like, anyway?’