The fun thing about cocktail parties is that you have to bring your official spouse and that is fair for everybody. The other thing is that your spouse does not have to be absent to the cocktail party without any reason because that can make a diplomatic crisis. Members of the family are sometimes admited to the party and it depends on how they are known for example they have to make their name for example in the American tradition when someone calls you by your first name it is because you are appreciated.