I don't think that it's being selfish at all that you don't want her there...it is
your wedding after all. I would explain to him exactly why you feel that way you do and hope that he understands and would take the feelings of his bride-to-be into consideration OVER the feelings of this trouble making friend.
I think that if the 'friend' is pushing the issue, then that really speaks volumes about her and her motives. From the sound of it, you guys have given her the opportunity time and time again to prove you wrong and she has failed. This is not a day that you can "get back" if she decides to pull her antics. And for what it's worth, I think that everyone, at some point in time has to deal with one of
those sorts...and a 'other half' who just doesn't get it.
If all else fails, appoint some of your tried and true attending girlfriends (bridesmaid)) to be on patrol to keep her in check. They'll likely jump at the opportunity.
Good luck and congrats on your upcoming big day!
