Should amir have told Soraya about his betrayal of Hassan before they were married? why or why not?

In the book The Kite Runner it stands
to reason that when his wife came clean about her past and shared her woes that it would
have been a great time for Amir to share his situation as well.  However, Amir was
emotionally still ashamed by his childhood actions and inaction.  He carried so much
guilt inside him and shame that he could not have told the girl he loved the
story.

IN addition, Amir was raised by a father who was
from Afghanistan and his values and the way he was raised had to be influenced by Baba.
  The men from the country are not usually used to sharing their feeling with women and
Baba had no way and also was known to keep all his feelings inside about her.  Amir was
also very ashamed about the incident in relation to his father so it would have been
difficult for him to risk opening up with anyone.

Amir
waited until the time was right for him.  I would have to say sice he was not ready, he
made the right choice not to tell.