If AD softens towards Bnai since she reminds him pof his past, lost love he should stop coming in between JB. Bani's happiness should then be more important than his revenge. He should realise love is more important than hatred. He should move on in that sense.
Him marrying Bani will kill his character. Not clearing Bani's misconception about JAi is still Ok if he is bent on taking revenge on JW. BUt how does marrying Bani serve that purpose. I would feel really bad for Bnai to get used like that. IF he marries her out of so called love then its not true love because as JAi said to Pia true love is putting the person u love ahead of yourself. HE can't do it knowing the person whom Bnia loves ( even if he hates that person) loves her more than his life.