I would recommend seeing each lady on an individual basis, and from that point, float the idea of doubles. Develop chemistry with those 2 ladies beforehand, and your doubles session will be mind-blowing
unless you wanna take a chance at having a less than deliteful encounter w/ the two providers you have never met, much less never been intimate with.
also, know what it is that you want to experience during that time. like, all action on you, watching them do each other, round robin (every one gets some delites), role play, etc.
once you know what you'd like, then you can find out if they're into providing that.
good luck!!!
and start saving up some cash - you're gonna need it!