I think we need to stop worrying ourselves about this. I've learnt that come what may, we can't change it and killing our poor little hearts about it won't help.
I will say this though, I do believe that Tanveer is the catalyst for intensifying what Zoya and Asad feel for eachother. After all, nothing makes one realise how much one wants something until the prospect of losing that thing arises. And on the Ayaan thing, I highly doubt that will happen, Zoya's tie to Ayaan has been highlighted thus far as that of babhi, whether it be through Humaira or Asad.
In addition to this, Zoya makes Ayaan look like a child, they just do not go well together at all. Let's remember Zoe ran away from wedding because she didn't want it, it was loveless, now that she has feelings for Asad, do we really think she'll go for Ayaan, another stranger, his brother, her sister's love? Also, Ayaan flirts with Humaira, obviously likes her, yet is afraid of marrying her, it would make no sense to have him want to marry Zoya as it is the prospect of marriage in itself that seems to scare him.
I hope my post didn't offend anyone, it isn't my intention, just trying to calm us all down. 😳