Asad will regret it...of course he will.
When he comes to his senses...whenever that is...right now he is a wounded lion.
And Zoya is RIGHT NOW the princess who silently tends to his wounds.(read- take care of phoophi, Najma)
When the right moment comes she will bring it up...or before she does, he will apologise.
RIGHT NOW, Zoya will not go fighting for HER RIGHTS , since the whole thing is not about th eslap...it is about Dilshad dying. A person dying is a million times more painful than ANY SLAP AND CUT. (Don't forget the cut!😉). And phoophi is the closest to a mother Zoya ever had.