I think Imran is just playing with Najma. His mom might have put him up to that because she knows Asad has a lot of money and will do anything for his sisters. She got a taste of that when he signed over some property to her so that she could allow Nikhat and Imran to get engaged. He did that for his step sister, imagine what he would do for Najma. I think Imran is selfish and is following his mom's orders and like she said today, he always listens to her and does not go against her.
I think he might have met Tanveer before Nikhat and even while with Nikhat. He is only getting married to her because of his mom's insistence. He cannot marry Tanveer because his mom would never accept her. He cannot stand up for himself and his feelings, and I feel that he has feelings for Tanveer and the other two he is with are just on his mom's insistence.
Anyway, that's just my opinion and theory. Anyone agree?