Cos he's just letting her do whatever, that way she wont hassle Anjali or Yug. Its basically like a metaphor if a dog is barking let it bark ... it'll soon stop when its not getting any attention.
So Pammi is the Dog ... and her yelling etc, she thinks she is in control, but Kavya is controlling the situation.
What is it with Ekta and all her dramas, people overhearing others on telephones etc, if you're having such a private conversation, then surely you can close the door!! isnt that what any sane person would do??