Nargis, I dont think they have regressed in their relationship. Arnav is learning a lesson each day from Khushi. Today he learnt the lesson to accept the changes in a person even if those changes may not be to his liking. Arnav couldn't stand to see La dressed in clothes that reminded him of the one woman he is desperately trying to forget. He let his intolerance known to La. After Khushi knocked at his conscience, he understood that he has no right to stop La from wearing what she pleases. I think with this came the realisation that it wasn't fair to dictate terms to a woman he wasn't in love with. In fact he did not have the right to dictate terms even with the woman he loved. The sorry he uttered was to Khushi for he was looking directly at her when he uttered it.
Agreed Opti...In trying to make some sense...the only reason I can think of why he went there to apologize was for Khushi...not La...to acquiesce that she does effect him...he does heed her advice...he is cognizant of the hurt he doles out.
What I found odd again was him surprised at her not liking La's display of affection...why is he surprised. I thought last week he was on a mission to make her confess that he affects her...but today...when he saw that she was affected...he had a dazed and confused expression...why? I would have thought that he would have been happy at her reaction...no?