I've seen this a number of times. In one of my clubs, some of the girls will start e-mailing out of the blue. Usually it's some excuse, like asking me a question about when an event is going or whatever. But, they keep writing when I reply, saying things like "it'd be fun to go to this place" or "what are you doing this weekend?". It's obvious they want me to ask them out, but they'll never actually say it. I don't really mind, I just accept that most women aren't going to be the first to ask (some are overly aggresive on the other hand). So, if I'm interested, eventually I bring up getting together and of course they jump all over it.
If you haven't already, drop hints...obvious hints...as close as you can get to saying "I want to meet up with you" without actually saying it. Then you preserve your rule and he might finally figure it out.
If that doesn't work, he's likely not interested and will reject you if you ask him out...that or he's just scared, shy, or just not very bright.