What is wrong with Naksh?

I don't understand his problem with Karthik. Being protective of your sisters is good but he is sometimes utterly rude with Karthik. In yesterday's episode he was being mean to Karthik for no reason at all. He was talking about doing "ehsaan" on Karthik, but what "ehsaan" did he actually do? It was Karthik who helped the family so much with wedding preparations and all. Instead of being thankful Naksh is being rude with Karthik. I understand when he is angry with Karthik for spending time with Naira and Gayu but all other things he is saying to Karthik is irritating. I actually like Yash, Ananya and her husband in that matter. They are actually very friendly and treats Karthik like family...

For me the problem is with consistency in story.

Ha u need to be possessive n protective about ur sisters but atleast be nice to a person who saved your mother for godsake.once his love story starts his mind will get diverted hopefully .