Is it possible, besides the fact that they must keep hope, that Kaine and Desiree as much as they obviously hate Terri don't believe she could really harm Kyron?
Regardless, I see in Tony's eyes he believes Kyron is dead. When Desiree talks about Kyron being alive or handed off to another, Tony just clams up and looks devastated. He knows.
Before June 4, I doubt that either of the parents thought that TH would cause Kyron's disappearance, or that she could kill anyone, especially a child, and especially Kyron.
Now Kyron is gone, and they think TH took him.
But hope that Kyron is alive won't go away, so to make that a rational hope, they have to convince themselves that TH was not capable of killing any child, especially him.
DY keeps talking about her motherly instinct. I opine that one reason she believes that Kyron is alive is that she also believes her mother's instinct would tell her if he had died. I think that's why she talks about her motherly instinct so much. It's not just guilt that Kyron did not live with her and she could not protect him, it's mostly that she wants everyone to believe that right along with her and find Kyron. There is no room in her mind and heart for him to be dead; it is inconceivable.
I understand a little bit about how she feels. I have been in a different kind of situation in which I was told repeatedly over the course of nearly two weeks that there was a
100% certainty that my son would die, and it could happen at any moment. I did not believe it, although there were times that I was desperately afraid. Many professionals intervened to help me accept the inevitable, but I would not, I could not. My son did not die and he has been perfectly healthy in the 16 years that have elapsed since then.
Sometimes, infrequently, and not until years later, I wonder what would have happened to me if he had died -- would I have died, too? I was that desperate for him to live and could not imagine life without him being possible. At the time I didn't think of it, but of course other children had died from his condition (all of them, in fact) and there was nothing special about me or my child to keep us from suffering that dire consequence.