Arnav's behavior -Is this a part of his mega plan?

Get a feeling that Arnav already knows that Khushi is innocent. He was outside Guptas home many times, what if he has learnt about Khushi & Shyam from the neighbors. He never wanted to tell Khushi about the marriage because he knows that it will break her but since she was planning to kill herself, he had to spit it out. Now that he has broken her trust, he is guilty and wants her to hate him so that she can leave him after 6 months. He knows that she loves him and that is exactly why the Holi confession scene was shown.

Seeing her behaving normally after such an accusation, Arnav can't take it. He is feeling more guilty. He provoked by dragging her parents into the entire conversation. His statement about why she doesn't give any explanation is for her act of hiding everything from him.

May be this is the mega twist that they are talking about :)