pia was pregnant with pushkars baby and she made believe everyone that she aborted the baby and came to walias house with full proof plan. she start working closely with jai and got the occasion (right time and right moment) to made him baihosh with meds and made him believe that she pregnant with his baby. she is using the baby as her hathyar to get into his life and out of pushkars life and so did bani out of walia life.
full proof plan
it makes lots of sense