Anonymous wrote:I am not Jewish but that has no regard to offering advice here.
YOU are hosting a dinner, YOU set the time and YOU have no obligation to change that. People need to accommodate themselves around your dinner not vice versa.
Remember he who excuses himself accuses himself...make no apologies and say the time is set and be firm. It is not fair to your or your other guests. Best of luck.
OP here. Thanks. Time is set for 6:30. I never tell my brother the "real" time because is routinely up to 2 hours late (at times just not showing up and never contacting us). I told him between 5:30 and 6 knowing he would most likely show up between 6:30 and 7. The girlfriend is going to get an unfortunate eye opener about how my brother regards family (he would never do this to a client or a friend--just immediate and all extended family).