Why Aliya refuses...

According the spoiler Aliya makes Rehan promise not to disclose Nafeesa's truth but Rehan breaks his promise and tells Zain.

This is what I think...Aliya know that Fahad will do what Zain did and give Nafeesa talakh.

She will worry for Nafeesa's kids that's why will want to hide the truth and be the Sacrificing Devi.

But Zain finds out he will want her back but she will refuse and tell him to hide this truth or else Fahads daughters will have to suffer along with Fahad and Nafeesa or makes him promise her.

To save his brothers family or binded by aliya's promise he will hide the truth about Aliya 's innocence and won't be able to stop Suri from planning his 2nd marriage but at the same time he will try to get Aliya back in his life.

Now this makes sense...I just don't want Zain give 3rd talakh.