I think that you guys need to tell him that it is okay for him to go now...that you will be okay with it....
http://www.buzzle.com/articles/the-challenge-of-death-and-dying-letting-go-of-a-loved-one.html
The Challenge of Death and Dying: Letting Go of a Loved One
In the presence of loss and attachment, it is still possible to let go with grace. How this happens will be different for each person, for each individual heart loves in their own unique way, and yet there are components that are similar, involving a deeper understanding of the soul's journey.
Beloved Ones, the passage into death is not one to be feared, but one that signals the completion of one phase of life so that another can begin. For in truth, there is no such thing as death, only ongoing life for souls in an ever-expanding process of exploration and learning. The journey is infinite, as are the capacities of each and every soul.
Nevertheless, the emotions created by the loss or anticipated loss of a beloved one are painful to the ones who remain behind, even when there has been a long process of anticipating such an event, and even when the loved one is elderly or quite ill. Even then, the ties of connection can remain strong and the difficulty in letting go can remain equally strong.
From
http://www.endoflifecomfort.com/death-and-dying/letting-go
What is letting go as your loved one dies?
ARTICLE SUMMARY
Bertha lay in the nursing home bed, in a coma-like state. She had not responded for weeks, and the doctors knew she did not have long to live. All the family surrounded her, except her grandson, the black sheep of the family. He was her favorite, but the prison was reluctant to release him. After many pleas the prison released him temporarily to see her. When he walked into the room and spoke, she suddenly sat upright in the bed. Coming to her he hugged her, told her he loved her, and he would try to do better. She smiled, lay down in her bed and died peacefully.
Letting go is the process of detachment from this world when facing death and dying
* It helps many patients to prepare for what lies ahead,
* Detachment from you may occur - do not take it as rejection
* It is a normal parting, from the family, parting from worldly attachments
* It is acceptance by the patient knowing that their earthly life will soon be over.
Giving our loved one who is facing death and dying permission to ‘let go’ may be the final gift they were looking for, to prepare for the final journey.