Well, the majority view is that Jai is a shadow of himself these days because he is not owning up to what he did (ONS). But when did he ever own up? Even in the PR Raaz he finally admitted to what he did only when he was forced to. And here it was just an accident. It is not like he murdured her mother. He could have confided in Bani earlier. Maybe she could have forgiven him. But no, he does not learn from his mistake. He keep mum about ONS. But here I would emphathise with him. I think he is not confiding about the ONS because it would hurt Bani deeply, especially her sister's betrayal. She holds her sisters very close to her heart. It is to prevent any further pain that I think he is keeping mum. In fact by doing so he is punishing himself more. A guilty conscience is more painful to handle than coming clean and handling the consequences. Bani is not making things easy by throwing her sister in his company time and again.
Talking about secrets, Bani is no saint. She too has kept some very important details from Jai. Jai needs to know the true nature of Jigs if he has to protect his industrial empire. He needs to know about how he lost his child because he is still in the dark about his life being in danger. The person who made an attempt on his life can still make another. And now keeping the Barnali matter from him. Who knows what complications that can result in.
Comparing Jai and Bani, Jai has only one big secret whereas Bani has so many.