After having the child, Keith initially loved the baby dearly. But when Lynley was two, he suggested separate bedrooms and began to grow distant from the child. It was as if he had been possessed by someone else; he mocked my questions and my love. He said, "Lesley, we’re just in a marriage of convenience. You’re asking for too much."

From then on, I saw him clearly and withdrew from his affairs, focusing entirely on the child. If his father didn’t love him, that was fine—I would show him all the love I had. But it turned out that the father and his son always get a special bond, and...