I agree that he shown special interest in Priyanka while she was an student where RAHMAN was an Faculty, but that was LOVE, and thats why he married to her, and she married to him happily.
Did RAHMAN abused/molested her ? Did RAHMAN ask her dad for ransom? Nothing dear, he loved Priyanka and he Married her. It was the TRUE LOVE.
If you think that it was LUST, than let me remind you that, KOLKATA has the biggest red light area for prostitution, he would have fulfill his lust over there, but he didn't do that, Instead he chooses LOVE and died for her LOVER(priyanka).
By the way, LOVE is the main topic/story of our 90% Movies in bollywood.