Jai never deceived Bani.How do you expect a man to react when he is about to loose or has lost his baby second time in a row. What he uttered was in pure desperation of safety of his child.
When he told Bani that he does not need anyone else not even a child to complete their relationship,he meant it cause he was unaware of Pia's preganacy. May be Jai was expecting that the situation will sort out in a more simple manner but it did not.May be he did not grasped the intensity of the situation.But his love for Bani is not fake. he question above eveythig thing else reamins , how is he going to explain what he did?
***Well put Mahimn! And actually at that stage, he only saw that he is going to loose or already lost his child again! And if he again has to choose Bani over something, it would definitely be Bani and Bani only! But in this case, Bani was not in the picture nor a parent in him had this thought in mind! B'coz that duffer believed that now Bani cannot get to know the truth as Pia will not interfere anymore! And he behaved very normal as a parent who would react this way when they see their loved ones in danger! So nothing wrong, when he said that he wants the baby at any cost and can loose anything but not the kid!!