Some really interesting discussions, everyone!
As much as I agree that Kuhu went too far, I don't really feel bad for Mishti. These sisters have always treated each other like crap -- this is just the first time Mishti got called out on her share of the issue. Messaging Ketu without telling the rest of them and then talking to Meenu at length even if it was by chance was not cool -- again, not technically a breach of their pact but also a very convenient exploitation of technicalities.
Kuhu feels like if she didn't intervene, everyone would have just followed the solution Meenu gave Mishti and praised her for solving the problem, completely forgetting that she broke their pact. It's the divorce truth reveal all over again, which was far from the first time Kuhu has seen events unfold like this. Mishti thinking she knows best and acting of her own accord and then getting praised for it when it works out is an age-old pattern, so I can see why Kuhu got triggered and way overreacted. Yeah, her blame Mishti thing is getting irritating but maybe she would stop if someone actually held Mishti responsible for once?
What she doesn't realise is that Abir was right there with her on the central issue -- he was also not happy that Mishti talked to Meenu, no matter how it came about. If Kuhu hadn't flown off the handle, Mishti's mistake might have actually been addressed and Abir would have held her responsible. So Kuhu essentially shot herself in the foot by not being able to trust that the brothers would be fair, and trying to take matters too aggressively into her own hands.
I think I am the only one who actually appreciated how Kunal handled it. His tone with Kuhu was not cool but he corrected himself once she questioned him and she backed down when she stayed back and let him deal with Abir. It doesn't come as a surprise to me that Kunal has double standards for Abir and himself, he has said it in so many words: bhai ki baat alag hai. Kunal has always been the silent pillar of pragmatism that props up Abir's "cool" banjara lifestyle. He may claim to Kuhu that nobody forced him into this but he has also told Meenakshi that he did everything to be the son Abir couldn't be for her. So I think Kuhu sees something extremely valid that Kunal, with his low self-worth doesn't, and as his partner, she definitely deserves a say. She just needs to continue looking for better ways to communicate this to him.