In Search Of
I'm not a big fan of hiring escorts for someone and not telling them... She has the right to know, as some people would be REALLY offended/pissed or more to find out. For instance, lots of people assume escorts have STD's, and would be PISSED that you put them at risk without telling them.
I understand your frustration at not being able to find a girl in the civie world to hook up with, but if you have to lie you should not be doing it.
I would suggest picking a moment when SHE is frustrated as well, THEN approaching the idea of maybe looking at hiring an escort...suggesting how hassel free it would be, as well as having no drama afterwards (like awkwardness with a druken friend, or a clingy girl that wants to butt in on your relationship somehow afterwards...). Also you have the bonus of picking a girl she really likes (instead of just one that is compliant) and of picking one out together...letting her have the final say on who it is.
If she declines, you can say play it off as a last ditch idea to try and bring *her* fantasy to a reality. Say you read about a similar thing in a men's magazine somewhere... 
If she chooses to wait to find someone through the same methods you've been trying, you at least gave her the option, and you will have a better understanding of where her boundaries are. Who knows? She may surprise you by agreeing, or maybe after thinking about it, coming back to it later and suggesting it herself.
If you want to foster an honest relationship with this person, don't lie to her about this stuff...
Good luck to you!
xoM
