text: This is a horrible situation to be in and believe it or not there are a lot of girls out there so jealous of a guys good relationship with his family that they do everything in their power to put a stop to that. Your brother will get over this infatuation, because thats alll it is, and when he comes to his senses he will realise that this girls jealousy and possessive, manipulative, self obsessed but insecure nature is coming between him and the people that have supported and cared for him his whole life. Blood is thicker than water. If he truly loves this girl however he will want yer acceptance, life is nothing without a secure loving family unit which ye seem to have.  Until he realises this however ye have to make the first move. No matter how much ye despise this girl ye muct accept that for now, they are together. Arrange a family meal and invite her. Show her that the concept of a loving family does exist as it seems that she doesn't understand that. Be open and friendly towards her and make her feel wanted, your brother will respect this and if he feels that she is accepted then hopefully ye will become close again. I wish you the best of luck and hope that my advice is of some help.