But who told Ayaan to take care of Zoya...ASAD, he told him that he has to protect her for his own sake, you guys always says that Asad is the sinner, he decided for Zoya and all, but did you ever think, what must HE be going through, while doing this, ASAD WAS NOT AT FAULT BECAUSE HE DID NOTHING, and from what he has been told, Zoya is ACCIDENTLY married to Ayaan, so he shut his own desires for what he thought was right, even when he knows that Zoya loves him, he had to do it, and as he said EVEN HE IS HURT!!! But have to do all this even when he didn't know anything, even when he was not at fault...
And about the defending thing, Zoya was always in Tanveer's plans to keep them away from each other, so Tanveer always filled Asad's ears in the wrong way to show that it's all Zoya's fault, so obviously he will trust his childhoud friend over a girl who he met 6 months ago...