It is not that Arjun ever deceived Ovi about how he felt about her, there has never been any attempt to pull the wool over her eyes on that score, she just refused to believe he could care for anyone except her. Looks like she has come out of that delusion herself and that has liberated her ;) she has more power now if she is no longer in love with him or has accepted that he does not love her. Good for her even if she turns negative. No girl should let a guy have that kind of power over her especially if he does not love her in return but loves another.
In the SBS segment last week where Ovi was waiting and Arjun walked in, both looked like they had stopped playing charades. Time to face the truth head on, bitter though it may be.