Finally I got time to watch the episode! I think the track's purpose is to make Mallu (😂😂) loose his patience: Kalyani is already having issues managing 3 kids and she has pretty much no time for Malhar and even less for herself.
When they find out that she's pregnant, he'll say enough is enough of this insanity, although I don't think she'll listen either... most probably, they'll have an argument heard by Anu, who'll run away from home and have a similar accident to the one she had that put her in this condition and she'll regain her memory and go back to normal.
So Pillu baby got slapped by Aaifi... by the time Kalyani's pregnancy is revealed, he'll be so insecure and unsure about his position in Kalyani's list of priorities that he won't be the least excited about the possibility of getting a sibling.