I don't think Ayaan was wrong.
Think about it this way. You have two sisters Nikhat and Najma, and you know that Nikhat is in love with a guy called Imran, and she is going to marry him.
Out of nowhere weeks later their engagement is broken and you find out your other sister loves Imran too and they want to get married, and on top of that your elder brother didn't even bother to tell you or the sister who had her heartbroken that Najma and Imran were planning to get married. Of course your elder brother will say I tried to tell you ONCE, but how pathetic is that? Just once?
Wouldn't you feel Najma betrayed your sister? Wouldn't you feel like she should've waited or at least warned you that she is planning to marry Imran?
Is Asad really that insensitive that he didn't even bother to wait a few days before going with Najma to Imran's family?
If he really loved Nikhat as much as he loved Najma, would he have so quickly gone and arranged Najma's wedding to the guy who broke his other sisters heart?
Think about it this way If Nikhat was in Najma's place and Najma in Nikhat's would Asad have done the same thing? I doubt.
If I was in Ayaan's place I would be the same. I would have witnessed the enduring pain of one sister, and I couldn't just forget that for the happiness of the other and that too within a couple of days.
Once time passes yes it would be for the better than Najma and Imran get married, but for the time being I think it is insensitive of both Najma and Asad for her to talk about marriage with the guy who broke her sisters heart just a couple of days ago.
With Asad I feel like he is more attached to Najma, but with Ayaan I feel like it's more to do with him witnessing a sister's pain rather than be closer to one or the other, notice how he was far more upset than even Nikhat that Imran doesn't love Nikhat.