Scheduling to meet the "other" hot girl at a MP

First, thanks to TER for your site.  I joined a few months ago and have learned a LOT from all of you.  Recently, I've encountered a "situation" which I've had trouble figuring out and hope to have your advice.

I began visiting a MP a couple months ago to see a certain advertising girl.  First session was great, non-rush, 2 cups, conversation.  She gave me her private phone # at the end w/o me asking for it when she found I'm single, said I should ask her out for a non-sex date sometime, etc.  

I decided not to ask her out as she's over an hour away from me, she seems to work a lot at the MP, and I'm just not as much of a night person anymore.  However, I did schedule a second session w/ her.  It was good, not as amazing as the first one but good.  She asked me if I'd mind buying take-out dinner from up the street.  I bought some for us and another provider there.  She entertained other clients and then returned to join us in the MP kitchen and we had an okay time (as I got to meet the other provider).  

I scheduled a third visit last minute.  She had me wait, squeezed me in between other appointments, rushed, apologized and said she'd make it up to me.  Due to confusion, a hot new provider answered the door when I arrived and assumed I'd see her (hot new girl) but was a bit put out when my usual said she'd take me in a minute and gave the new girl a different client.

My "usual" girl recently surprised me by calling and leaving a message on my cell that she misses me and hinting she just had a birthday.  Honestly, I'd rather have a session w/ the hot new girl who I briefly met and chatted with and can't get out of my mind.  I honestly was waiting for a day when my usual was off and the hot girl was working.

Question:  would I be hurting feelings if I scheduled w/ the new girl instead of her?  Should I care?  Should/does she realize it's "just business?" My usual seems to work daily while the hot new girl is more part-time and usually on same days as the usual girl.  My usual seems to be in charge of answering phone for all girls, too.  

They do doubles.  Might that be the answer - to schedule for both?  Sorry for the long story - thanks.