Yes you are right that Siddhi should tell everything to her hubby. I agree with you. Raveena should be exposed every time. But as kunal have not full faith on her ( like gaurav case, rohit case he believe due to vikram) she also not have full faith on him- because of his anger, capability. She performs much better but fails due to witcha's crulity. Kunal also fails due to them. now he just sits in jail looking helpless and blank. Is he going to accept defeat and say oh well, can't do much. When Siddhi was charged, there was still chance it was a real accident. But if Kunal is charged, it sure is a plan to trap him. So if he can get Siddhi out of this trouble, can't he think about himself as well. If not for his own sake, how about for Siddhi's sake? He can think Siddhi won't be able to live without him and who's going to look after her? So Siddhi and Kunal are same- careless and not alert. but what is Kunal doing? Kunal is not someone who just takes whatever life throws at him. He promised Siddhi he will fight all odds and nothing will come between them. So he can still try to figure a way out of this mess. He has not shown his intelligence to siddhi so she feels risk