Only Zoya can call him that because she never means it and it's an affectionate way of calling Asad hers.
Please guys, stop calling him that. It's hurtful. He's one of the most compassionate and loving person I know. His character is charming and he has been hurt so much that he doesn't want to inflict the pain on others.
Try to understand him for a change.
I'll go back to preparing for my SAT examinations. And I don't mean to offend anyone with this post. 😕