A very difficult question indeed. I think a lot depends on the secret that both Roshni and Jai are hiding from Bani. Jai's family members do have some inkling (a very faint one) b'cos most of them do not like Roshni and they r alays telling Jai to stay away from her.
So, if the truth is indeed very bitter and if Bani's faith on Jai wavers, however much in love she is with him, I think she will call the parting shot. Or maybe, she will leave the Walia House along with Rano, just after Mausi leaves.
So, its definitely up to Jai to bring her back into his life, when he starts realising her true worth and also that he's unable to stay away from her.
Since their marriage has been kind of farcical, yet both of them r now gravitating towards upholding the basic vaues of this ancient institution and are moving towards each other just as two celestial bodeis are attracted towards each other and move around each other on their celestial paths.
But this time, i think Jai will have to do all the coaxing.
And will probably truly understand and feel the meaning of the song 'aadat' which they keep on playing to express the state of his broken heart. I have a feeling that what we have seen for Pia is nothing compared to what we are gonna see for Bani. 😉