Tamatar!!!
All three of them are to be blamed for the situation that they are in now. Zoya should not have run away on her nikaah day, Asad should have at least talked to Zoya before taking a decision for her and here it comes, Ayaan NEVER EVER should have asked his bhaijaan for his bride. That is just not acceptable at all.
Blame the naqli nikaah wala thing on muqaddar, fine. Nikhat's life was more important for Ayaan than anything else at that moment, fine. But, come on there were really some other ways to solve that situation. Unfortunately, that is the way the CVs wanted to do and to show.
Coming back to Ayaan... He promised that it willl be just for seven days, only till Nikhat gets married. Marriage ho gaya, did he tell any of his family members about the 7 days pact? Nope. He promised that everything will be fine. How did he think he was going to do that if no one in the family knew about what was going on behind their back between Asad-Zoya-Ayaan...
He himself does not even know how to get out of this situation so he really should not have made any promise to anyone...