The reason I'm saying this is that Sahir is playing with Aarzoo feelings because two reasons
1. If zaki doesn't marry samaira his 1000cr dream company is a dream and Canf prove it to zeenat
2. He also plans to humiliate Aarzoo n prove to zaki that Aarzoo is after money
Obviously zaki is a heartfelt character who thinks from the heart and sees things as they are and doesn't look between the lines so he may step up and marry Aarzoo
And then we will have something like
Zeenat coming back
And Aarzoo married to zaki n Sahir married to zenat but Sahir n Aarzoo love eachother n keep crossing boundaries
I think that's what the story is