That was my way of trying to figure out when it was conceived, of course. If I knew the due date I’d be able to work out when he’d slept with Emma. There were apps that would tell me that. Not the exact date, of course, but the week, at least. I’d read that five days before ovulation was the fertile window. Five days. A working week. A very long weekend. The thought of finding out when she’d gotten pregnant made me feel ill. I knew I’d go back in my mind to that week and think about how he’d acted toward me. Had he hesitated as I’d come into the office one morning? Had he felt a surge of guilt? Was he about to tell me that all this wasn’t a good idea and that I should look for another job? Or had he given a self-congratulatory secret smile, knowing he’d gotten away with it, sleeping with two women? I felt sick at the thought of that.

“No idea,” said Sarah. “Jane came in to tell us about it; she was very excited about becoming an aunt. Her own children are in their teens now; she was looking forward to holding a new baby again.” She paused for a few minutes, then said, “I still can’t believe you were having an affair. You don’t seem the type, somehow.”

“I’m not the type, whatever that is. I just loved him.” I softened as I remembered. “And he loved me.”

Sarah looked at me as though I was the most naive person she’d met. “He was married, Ruby. And so were you. It was never going to end well.”

“I know, I know,” I said. “It’s unforgivable. But what he did to me, encouraging me to leave home to be with him and not turning up, well, that was the greatest betrayal.”

“I think his wife might disagree with you,” said Sarah quietly. “And Tom, too.”

I winced, wishing I’d stayed in that night. Why was I putting myself through this?

“What about Tom?” she continued. “Did you tell him you were leaving to be with Harry?”

“No,” I said quickly. “No, I didn’t tell him anything. If you see him, don’t mention it, will you?”

“Of course not. I doubt I’d see him anyway. But why did he think you were leaving him?”

“We hadn’t been getting on well,” I said. “Or rather, we only got on well because I did whatever he wanted. I wasn’t happy at home.” I hesitated before going on. Some people just don’t get it and I had a horrible feeling Sarah was going to be one of them. “Tom’s hard to live with. He’s controlling. Possessive. I’ve wanted to leave for a long time.”

Sarah seemed confused. “That’s not how he came across when I met him.”