I am going to try to organize a night  for myself and 2 close friends using TER.  I am trying to organize a 12 hour session/overnight with 3 ladies.  

Is it realistic to ask or expect each of the guys to have time with each of the 3 ladies or does each lady become exclusive for the entire session?
Will 3 independent ladies allow me to organize a night like this or do I need to find one lady and ask her to bring 2 friends?
How do I ask for these things politely when I PM each of the 3 ladies I have found?

This is unchartered territory and I have the budget to accommodate this big plan.
Frequent fliers advice much appreciated.

It is best to ask the lady to bring two of her friends so she feels comfortable plus don't discount the girl on girl action if that's something that you are interested on.  Typically the interaction among girls is best if they all know each other in advance.  
I think if you plan on spending time with each girl, privacy should be provided so each girl/guy has a room. I have done it before and if you explain everything in detail, it could work marvelously as long as everything is organized proficiently and harmonically ensuring comfort for each party involved.

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there are oodles of providers who would love a session that you are describing..most websites will list the girls and their availability..having a well-reviewed lady with doubles experience is the way to go..she will organize it for you provided all of the guys are properly screened..you usually go with the flow on who is with who..it all depends how adventurous you and the ladies are..bring some major coin and explore the possibilities..

to have spent time with the lady previously whether it be a 1 or 2 hr. date or preferably a dinner date.  There needs to be a comfort level.

Likewise for doubles (and triples).  The ladies need to be comfortable with each other.

Sounds, like fun, but all parties need to get along & business matters taken care of prior to play.