Dev is getting a taste of his own medicine.
He is a successful businessman, and knows how exactly a decision can impact, in professional or personal life. At the heat of the moment, he could think of only his mother, who had taken a drastic step. He had just learned newly, that his mother did not approve of Sonakshi and hence she hurt herself so badly she could have died. So without looking at the odds he made his decision. He feels he has committed a crime by falling in love, and was so blind to the fact that his mother was affected by it. A son who only wants his mother's happiness.
Sonakshi on the other hand, tried to calm him, tried to tell him that it is too early to take a decision, wanted him to convince his mother, wanted him to stand strong, but he buckled at the first sign of trouble, he was not in a state to listen, he wanted her out. He did not want his mother to see her, lest she takes another drastic step and hence, He fires her from her job, so that she is not seen anymore. At that point, it was only his mother who mattered.
Dev realized the consequence of his actions only after he had brought his mother home safely. Inspite of loving and missing her, he could not take that step to go over and tell her that what he did was a mistake and they could try and convince his mother. He never assured Sonakshi he would be there for her.
A person who has been dropped without consideration, has no ego, has only hurt and has lost all confidence. You cant forget that all the love she had for him was rejected, and you still expect her to understand him and get him out of his depression. Why? She is no God. But, yes, she still loves him, and be it in the pretext of shouting at him, or reprimanding him for stalking her, she meets him, because that's the only way she can have a glimpse of him.
When she is screaming again and again, that their relationship is over, she is trying to convince herself more than him.
She wants to know if Dev is well, hence goes directly to his house to face the mother, knowing that she is baring herself to scorn. In all of this, she is aware, that she was his only friend, who he could share anything, and offer solace or advise, and knows he needs her, but what about him, he is not willing to meet her even halfway. But he is ready to conclude that she could not fall out of love with him so fast.
I love both Dev and Sonakshi and hope we will be able to see happier times soon. But unless Dev understands what love is, and what love gives, its no use for Sonakshi to be in his life. Because she is love. Be it in her heart or in her actions or whatever she does, its love all over.