Leo Woman, Aqua Man

I've never been interested in an Aqua, and now, I can't seem to shake em'. There's this Aqua that I can't get outta my head. We met in an odd way, actually. We used to work in the same bldg, and would see each other in passing. Then, we eventually started to engage in small talk. FINALLY, we actually introduced ourselves. This Aqua, however, has thrown me for a loop. E.g., when I told him it was my b-day (last July) and that I was taking Arabic classes (in the same conversation), he took the time to look up how to say "happy b-day" in arabic, and e-mailed me happy b-day in arabic. He finished his e-mail by saying that he'd be happy to go out for drinks any time! Another e.g. is when I told him about an event I was doing two months b/4 the event date. I never mentioned it again and didn't formally invite him. The day of the event, I got an e-mail from him, wanting to know where and when the event would take place...and he actually showed up! FINALLY, he never mentioned having a g-friend, at first, until a couple of months later when I mentioned my splitting from my b-friend.

NOW...I barely talk to him! Primarily because he no longer works in the same building. I did wish him a happy b-day, and offered to do his b-chart as a b-day gift (which he was THRILLED about). We bumped into each other a couple of weeks later, and he asked me to continue walking in his direction so we could keep talking. Then, I stopped by his office yesterday to say hello (which he invited me to do once we reconnected). It's weird, but I do think there's some interest there. However, he has a g-friend, so there's no sense in me sweating him. BUT, I can't stop thinking about him! I'd at least like to get to know him better, as a friend. I just don't know how to do so w/out things being awkward because of my feelings for him (and because he as a GF). Any advice? What do you make of the examples I gave above? Is this how an Aqua normally acts w/ random ppl?