Is this an attempt at a hookup, or just a friendly gesture?

In my freshman year of high school I had a hopeless crush on an junior. He knew I liked him, and was always super nice about it, but in my sophomore year he started dating someone else and I got over him (we remained friendly). By my junior year I'd completely moved on, since he had gone off to college. I just finished my freshman year of college (his junior year) and we recently saw each other again at our high school's graduation. I was dressed well enough to catch a few eyes, and today I got a Facebook message from the guy I liked, in which he gave me his phone number and told me to call him so we could eat lunch and "catch up or whatever". I certainly don't want to read into this too much. He could, after all, just want to eat lunch (which I'd be totally fine with). He could also want a summer hookup, which I'm also kinda fine with. My only concern is that if it's the latter, it would be VERY awkward. Am I overanalyzing this? I've moved on, but we're both home from college for the summer, so a little fling certainly wouldn't be a bad thing.