'He doesn't want to include Mitchell in every meeting'. Why not, what's he got to hide? If he accepts the principal that the USA, through Mitchell, is the (supposedly) honest broker and mediator, why would you want to exclude him? The answer is pretty obvious: the USA is not going to agree with much of what Israel is demanding and will inevitably have to say, we don't think this and that are reasonable. As the Pal's negotiating position is generally accepted by all except the Israeli hardliners, there is nothing very controversial in it that even the USA would take exception to. So Bibi is going to find himself in a minority of one on many issues and in Mitchell's headlights. Hence the bid to do the bullying and excessive demands in private one-to-one meetings. This will never fly, everyone is wise to it and the Pals are obviously not going to fall the same tactic this time!
PM: We'll surround ourselves with fences in defense against the wild beasts around us (Haaretz)
from the article: Abbas wants a trilateral meeting between aides before direct talks