Most Helpful Guy
He could be on the site to talk to friends he made there. Or it could be more. It doesn't really make sense that he would be looking for a another girlfriend while suggesting that you get back together. In any case he's not going to say yes to a question like that!
A better way to judge his motives for getting back together is to consider what you already know about him. Did he have any kind of tendency to stray when you were together? When you discussed your roles for the breakup, what do they say about his motivations for wanting to start over?
You haven't mentioned whether you want to get back together. Since you broke up with him, are you satisfied that the reason for the breakup is resolved? Does that discussion speak to your doubts at all?