The Curious Incident of the Dog in the Night Time 2

I disagree with the reasoning behind Ed keeping his mother's letters from Christopher. Ed claimed he was doing it to protect Christopher from knowing that his mom abandoned the family but if I was Christopher, I would want to know the truth. If all my life I thought my mother was dead and one afternoon discovered that she wasn't and I was being lied to, I would feel very hurt. So, if I was Christopher's dad, I would have told Christopher the truth to save him from dissappointment later in his life.