Ryka, good post dear. Coming from you is no big surprise being the staunch supporter of Milsi you are.
Agree that Milsi has behaved exactly as his character is expected to behave under the cicumstances. But just as his character has the right to behave the way he did, Prachi's character also has the right to behave as she did. We are forgetting that Prachi has always been portrayed as the sacrificing queeen, a girl whose love for the people around her surpasses anything she feels for herself. She willinglyly sacrificed her childhood sweetheart for the good of him and for the satisfaction of her sister, even if it meant that she herself would end up heartbroken. She agreed to marry Milsi, a total stranger at that point of time, for the good of her family. She put up in untold miseries that Milsi inflicted on her because of her sense of duty to him and later because she fell in love with him. There is very little she expects from the ones she loves. A small gesture on their part is enough to wipe out all the wrongs they may have done in the past. Take the instance of Milsi buying her the saree in the rains. She was so touched by that gesture that she was willing to forgive and overlook the near rape that happened not long before that. Despite Milsi swearing by the holy fire that he will break all realtionship with her because he thought she helped Suki and Saket elope and get married, she was quick to forgive him. She was even defending him in front of his father a few hours later. When he complied with her request to get Suki married to Saket, she was quick to acknowledge it.
Coming to the baby raaz, there can be no dispute as to her foolishness in handling it. But she was never shown to be very smart. The basic motive for her actions was to safeguard Milsi's honour and prevent him from being heartbroken. She is only too aware of his deep love and concern for his sister. Remember in the rain scene when she tells him he needs to come home, if not for anyone, but for his sister who depends on him. Again at the waterfall scene she tells him that she treats his sister as her own and would want to see her always happy because her unhappiness will cause him pain. So preventing his heart breaking from Suki's betrayal is more important to her not becasue he is not improtant to her but because she thinks Suki is more important to him than his own wife.
One cannot immediately blame her for that because if one excuses Milsi's behaviour on the argument that although he has found bliss in Prachi it has been for a very short time and his trust has not had time to take deep root. Now the same holds good for Prachi too, is'nt it? She too has not had much time to experience Milsi's undying love. So she still thinks Suki comes first for him and she comes a poor second. She feels that he would feel less betrayed if he thinks that she was the baby's mother than if he finds out that Suki is. After all his bond with Suki goes back a long time before she even entered his life. (She has not realised that she has come to totally envelope his very being even in this short time just as he has not realised that he is the very breath she takes.) The man even left town to ensure that his sister's future is secure and people dont take advantage of them. Now if all that comes crumbling down because of the baby raaz, it would be too much for him to handle (or so she thinks).
As I said in another post, had she witnessed him still heartbroken when she came looking for him in the chawl, she would have broken her silence. She loves him too much to see him in pain. But when she encountered the familiar accusations, sarcasm and pure spite from him she thought his anger at her was way better for him than his heartbreak when he knows about Suki. She thought he will be able to cope better with her betrayal than Suki's so she maintained her silence even if it meant she herself was losing big time. Only she miunderstood his anger. She has not realised that the anger is only a mask for his pain.
Coming back to the topic, Prachs did exactly as her character would do, take the blame for others for their happiness (as she see it). Now Milsi has to make a decision if and when he comes to know the truth. Does he want Prachs in his life despite her major short coming? Prachs has accepted him with his. Does he have the strength to accept her because this will not be the last act of sacrifice on her part. She will continue to do that through out her life. Is he willing to pay the price for it in the process? If not, then he better leave her. But he will also have to consider never ever finding true love in all his life, for no one can replace Prachs in his life.