They fear if both were there a fight would break out and ruin the party.
tries to play it safe, both don't blame him/her for the meet...
But Its a bad thing to do.. he/she have to make a choice.. its either me or her..
I think it's usually because they take sides after the divorce, Sometimes because of the past relationship in terms of who was the friend or the partner of the friend. That's what will dictate who gets the invite. It seems to be normal and probably done to save any embarrassement initially but its my experience that whatever happens at the beginning seems to carry on for ever.
Depends on who gets which friends in the split...silly highschool games, but that is the way people are.
would you prefer to be ignored?