I believe the house sale will still stand. It is up to the new father to provide and I do not believe it will have any impact on the court order. I am not a solicitor but I am conducting my partners divorce settlement. I doubt any judge would overturn the original order, especially as his eldest son actually no longer lives in the former marital home. If any changes could be made to the existing order, the they would probably be in your boyfriends favour as it is in place to provide a roof over the childrens head, and given that none of them reside at the bhouse any longer......just a thought.
I have a brilliant website you can go to for answers. www.wikidivorce.co.uk