I know everyone hates what abha is doing right now. She is making whole women nation embarrased. She is a married woman. How can she even think about marrying another guy???
If she is really scared for her fathers health she would already tell them because if they come to know after the wedding EVERYONE yes EVERYONE will despise her. But if she tell now not everyone will hate her.
Now to the main point- Karan married abha kind of forcefully. No offense to anyone. I love karan's character too. But Karan kind of pushed her into this. Karan could do something else to punish his father and help abha and make her love him more. Because abha doesn't love Karan enough.