I see it as a case of two people with differing dating views/styles. What works for you or is preferable for you is not his preferred way. I'm thinking that maybe learning of this difference was a shock and a disappointment, because those long conversations were so pleasing and there seemed to be compatibility in a number of areas. Maybe some expectations started to form...and learning you were not singular in his interest felt hurtful!
Yes, I would agree. But, I also believe that he should have been upfront that he was currently dating and meeting several women, and, in fact, apparently in a relationship with one woman (6 dates and counting and apparently some physical intimacy from what he told me). To me, that is not just meeting people, that is being in a relationship. And, to me, that is potentially very hurtful as I have never failed to see someone get hurt if someone is telling people he is looking for someone to marry and is dating more than one person. Unless that person is just casually dating or doesn't care, she is going to get hurt whether she is the one he is/was dating first or whether she is the one he is meeting (after many messages, much phone time, etc.) while he is still in a relationship with the first person. I have seen so many women friends through so much heartbreak just because of situations like this! And, of course, this has also happened to me in the past which is why I won't meet someone who is in a relationship.