Can I be friends with him again?

Okay, so I dated this guy about four years ago. We stopped talking (as is usual in Jr. High) for the years and pretty much ignored each other...until this past school year. We started hanging out in a small group again (one of his friends is dating my best friend), and old feelings came back on my part. But he told me that he doesn't see "us" happening again. Fair enough, I can't control that. But, it has made me realise what a great friend I lost four years ago. I want to be friends with him again, but how can I go about doing that without falling for him again?

Let's see...I broke up with him way back then, and he *seemed* okay with it, if my memory serves me correctly.

Anyway, anything you could think of would be helpful.