Yash realized what he had done with Aarti till now...
He understand Aarti's condition and her affectionate love towards him. He understand how Aarti afraid of him and his anger and started to feel guilty.
He also realized Aarti's place in his, his kids and family's life. He started Aarti hunt operation with determination... finally after lot of tried and hard work finally he found his son and wife.
AND from that very point...we are seeing BIG changed Yash. He is looking at her all smiling, affectionately and lovingly. He is opening keep staring her beautiful face. AND with CHAI (tea) scene its very much clear that now Yash must have realized that its not just a attraction he feels towards Aarti BUT its love.
Finally it seems that Yash realized LOVE and fall for her!!!!