Most Helpful Guy
Well if he isn't sure, either you can talk to him straight up and ask him what it is or stop thinking about him and just live your life, and if by chance before you find someone else if he comes to you, then you can decide at that moment what to do.
Most Helpful Girl
Just because two people Breakup doesn't mean they can't and don't Makeup and that it's Goodbye, my love forever. And with an "EX" who still Marks an X in his own softie spot, there is usually motive in mind, should there come the time, that down the love line He... Has told me he loves and misses me...
He is most likely Missing the Kissing and the history you both shared and is Comfy in knowing you are there for him. He is Obviously not contented to find love elsewhere because he knows That... Love is where the heart is and it is close to his heart at home with you.
He isn't Ready to be in this Real relationship right now, although he wants you in his life, minus some strife that you both may have endured as two birds of a feather.
For now, Sticking together, to finish the phrase from above, go slow with his flow and learn to nurture and nurse being 'Friends' first so it can Begin a fresh Beguine of learning from your past mistakes and a possible chance at a new romance,
However, be your own straw boss and take control of this sticky situation which could go south as well. If it seems like it is heading in the direction of a Friends with benefits factor, lay some rules down, should you not want to take that step down That problem path.
Good luck. xx