I watched their confrontation again in hopes of understanding it better. I am still confused about a lot of it 😆... but I am certain about one thing now that editors have not kept all the dialogues in the scene to reduce the length of it and the end result is a jumbled up puzzle with missing pieces!
Meenu tells Abir that the world is going to laugh at us.
Then Abir consoles her saying that if that man left you then the mistake and loss is his, not yours. At that time they are standing quite close too.
Next moment Abir is standing in a different position/angle and further away and argues in frustration that he really doesn’t understand why they are discussing that man!
Meenu’s dialogues are edited in some parts, so Abir’s arguments look totally out of place and some of their conversation is not making sense here 
Anyways, moving on... so Let’s dissect Abir’s arguments:
Just to protect her fake self respect, Meenu brought Parul to the house, but then kept her as a servant.
If she really thought that Parul brings her embarrassment then why did she even bring her to the house in the first place and let her stay for this long?
She considers Kunal as her son, then how can his mother bring her embarrassment?
Kunal is as much a son of this house as much as Abir, so his mother(Kunal’s mom Parul) deserves the same respect that she(Abir’s mom Meenu) gets.
Since Meenu is the one who started all this by bringing Parul to the house in the first place, Meenu has no choice but to accept this truth.
Ok, so in a nutshell, Abir’s point is that if the two brothers are equal sons of this house - Meenu herself has always established that (at least to others) - then their mothers should be treated equally too and since Meenu herself has started this by bringing Parul to this house, she has no choice but to accept it this way now.
Phew, while penning this down, I understood it myself too 😆😆
Thanks for the post 🤗
EDIT:
Some more thoughts on what Abir means by "equal status for Parul" on page 9:
https://www.indiaforums.com/forum/post/153004099
Edited by SheThought - 5 years ago