What you really want is to see great chemistry between the ladies first. If they are into each other, implying they "trust" each other, virtually all other activities with you will be a natural extension. Ideally, they will get off on sharing with each other MORE than "working" just to get you off.
Not a bad idea to set the tone with some beverages (in moderation) and chatting clothed for a bit at first to settle nerves and build rapport. Keep it light and funny. Don't make this out to be some epic fantasy moment, even though it totally is! 
At an appropriate time suggest they kiss, or explore each other's bodies a bit. That gets the clothes moving in the right direction - down onto the floor.
Next, no script necessary. Just read the room and do stuff that will them feel good and ask for stuff that will make you feel good.
Caveat: You need to decide if a "boundaries and limits" chat it necessary before the skin-to-skin stuff starts. Nothing can kill the mood faster than trying something like anal only to see one or both freak out.
Also, as with any BCD date, I suggest keeping some bottled water in the room, a few hand towels, and other stuff like extra lube. And be sure to lay out extra towels in the bathroom along with other "girl" products like tooth-paste and brushes, clean hairbrush, etc.
Life is good
The Cat
You what's funny is there is so little good advice on line.
Everyone is worrying about boundaries and how not to offend the other party (jealousy, etc). lol
I've read your advice and only wish we could have put some of it to use, but atlas, my #3 got sick as we were about to meet up, so I gotta save up all my energy for later.
So my threesome is back on for tomorrow and I’ve been pumping my #2 for some basic choreography ideas, but she insists I’m over thinking it.
Then it hit me: you know, each girl we are with usually has a number of “talents” that makes her stand out….but typically, it’s nearly impossible to really find the true 10/10.
For example, my #2 loves to suck pussy and is amazing with anal action. #3 does neither but is extremely flexible and athletic to where no Kama Sutra position will be overlooked. #2 is beautiful with gigantic boobs, #3 is good looking with a super tight figure and ass.
I’m just going explore endless DFK with #3 (not a favorite of #2) while having #2 drain me dry. #2 will keep the F-F action going while I’m in her ass…etc.
Yep: the perfect “barbie gone wild”
