If in a flashback Dadaji or Dadiji was unwell and they needed money urgently and BP was in the US. he tried desperately in every way but could not arrange the money in short notice. At that time a woman who loved him although he was already married puts a proposal that she will give him the money but he has to cut all ties with his family. Due to this he cut all ties with his family with a heavy heart. But all these years his heart was with his family, BM and kids so the other family threw him out. this is revealed by somebody to the family and they remember that just before BP cut ties with his family he had arranged money.
This is just my guesswork. If this is the case then does BP deserve forgiveness.