Unsure (long post)

I noticed a guy at work a while ago; at first I thought nothing of it.

I saw him wondering around the office a lot and just figured that he must work on the same floor. Some time passed and he disappeared completely. I forgot about him as I was going through a lot of upheaval (new job, house hunting etc).
I think about a month later he re-surfaced and I started to see him more often around the building. I bumped into him a couple of times and whenever I did he'd start blushing and become all awkward. Socially awkward guys are nothing new; especially when they're in an office (hate to say but IT workers are prime examples of male awkwardness).

Anyway getting to the point. I bumped into him when we were both getting a drink in the canteen. I was in a really chipper mood and wanted to talk to someone. So I started talking to him..and we've been talking since. Problem is I'm not a permanent fixture, I'm an apprentice. So unless I get an extension or a job next year I won't be around.

I only see this as a problem because I've dealt with a guy like him before in college- shy, hesitant, awkward. I spent ages trying to figure him and by the time he plucked up the courage to ask me I was with someone else.
I know I should grow up and just ask him for a drink. But it's not that easy for me. This sounds really arrogant but I've never had to ask a guy out before, they've always asked me. When I try to broach this kind of topic I either waffle or clam up. Every time we meet even if it's briefly, he looks at me expectantly, looks like he's going to say something then walks off. Which I find confusing.

It sucks because he's the first guy I've liked since my last partner. If any folk can pitch in any ideas about how to proceed, I'd be really grateful. As in all honesty, if I knew for sure that he likes me I'd swallow my awkwardness and gladly make the first move.

FYI- He's a Virgo. I'm a Cancer.

Nothing to it but to do it...