I'm beginning to think it's Amar. Sure, even Sagar believed everything Sindoora said. He even believed Sindoora over his own wife. But, however nonsensical his reasons seemed to us, to him, they were justified. Sindoora was his sister. He didn't even know Vidya, and suddenly he finds out he's married to her. So he may have reason in believing his sister over his wife.
But does Amar even have a reason to confide in Sindoora? He believes her to be a kind person who saved Divya's life. Ok, thank her! Show her your gratitude! Don't write your life off to her
Amar, seriously, use your brain!!