Dude, I'm paying her to leave. Not to fall in love with her lol
I could see myself with a given lady. Just meaning her personality type fits well with what I look for in civvies. But no, I've never really fallen for one in the true sense of the word. But especially when I am with very "real" ladies that I get along great with - it does make me think perhaps it's time for me to get off my butt and put in the effort to find and cultivate a real relationship, instead of spending so much time playing this fun little game.
I've been seeing a FBSM provider for a few years. She is ahem "more mature" so closer to my age. We have developed a real closeness and spend as much time sharing our views on the world and daily lives. We also talk on the phone just to keep in touch. So, yes, there is definately a connection, and I wonder what life might be like with her. But, I also wonder if she'd have ever been interested in me if we had, say, met at a cocktail party. I don't regret the money I pay her (after all if I took her to dinner and The Kennedy Center it would more money) and don't really feel any jealousy knowing she's providing FBSM to others. I'd certainly be jealous if she provided more benefits to someone else but she assures she does not and I am confident she doesn't.
So, I'd say I have fallen for her but I guess I'm old enough to maintain some perspective.
It keeps the blood flowing.
We are all only human after all. Even us providers. 
It happens. I myself have never fallen for a client but I know girls who have. I know some that have been in short term and long term relationships. Not my bag of chips but it happens. we can be friends.
like Chris rock said" They say: never say never. well, i'm saying never!)
can't fall in love with someone I don't trust.