Arnav's public private behavior

He will defend her in the public and even in private but in private he can not control his emotions. He wants to hide it in front of her at any cost. He would not treat her in any manner which could hurt Khushi in public. That's just invitation for many problems. In private he puts up the hatred facade. If he starts treating her all lovely dovely in private then there is no character called Arnav. There is no point for his hatred. Thats the crux of his character. What will he repent for when the truth of Khushi comes out?

So he wants to make sure everything is fine at the family front. Less problems with Khushi, more time for him to tackle Shyam.

He's meant to hate her at the moment if he's nice to her or defends her in public, he can always say that it was to show people that they are a happy couple, but he can't do that in private even if he wants to as he doesn't want her to know he cares and can't give an excuse for his behaviour.