My best friends hate each other?

you should tell them that you understand they have issues and problems with each other but also tell them you don't want to be in the mix of it all. And if they were truly your best friends they would understand how much it pains you to be with them and in the mix. Also tell them if they can at least try to be nice or kind to each other around you. So that you can have a good time around both of them. Hope that helps. Good Luck.