This Arhaan is mentally unhinged. Firstly he hides this child thing, chalo MAYBE it is scripted but on top of that he tells her in the end, i only hid this small thing from you, YUCK you basically act like your child is some expendable secret. I don't personally think Rashami has forgiven him but rather does not know how to react, in the long run if she does, then god save her.
Now instead of repenting he is talking SHIT about her! My gut feeling is he knows their time wont last and is starting to separate from her before he gets dumped out of the game.