Even if Roshni forgives Sid after sometime, DD won't forgive Sid and Simran. DD would have taken all Simran's insult personally, so she would surely hold a grudge against Khurana's. I always used to say DD hates cheaters, however rich they are she hates cheaters since her husband have cheated her (I think). Thus, DD would now equate Sid with her husband and would never allow Roshni to get back to Sid.
So now, first Sid would have to win Roshni back. Then again he would have to win DD's trust, which is very difficult. Even when Roshni forgives Sid, until DD agrees I don't think she would go back to Sid. B'coz once she had prefered Sid over DD and the result according to her is really bad. So, now she would prefer DD over Sid and I'm sure she would agree for another marriage if DD brings it up.😠Now Sid will have to start everything from the scratch, winning back Roshni first and then DD. From the promo it looks like Sid would do something to give back the properties to DD. 😊 So, Sid get back to action fast and we would soon see more of DD - Sid Mahabharat (I'm excited