I see you state that he is a lot older than you. Do think about that if you intend to take his possible interest further. Large age differences can work, but can have additional problems you'd need to cope with, and there is the worrying thought that if this gap is too large then is his interest proper ? Does he have an improper interest in you, Or, on the other hand are you describing an improper crush you have on him ?
Assuming it is proper.
From your description if sounds as if he might be interested in you, but is rather shy. Or maybe he sees the age difference between you and opts not to follow up on any feelings he has. Difficult to tell as it depends on your interpretation of his "being nicer to you" and "catching your eye".
As a general rule, men aren't good at spotting subtle hints. They also completely miss average hints. And blatant hints, well they go over their head totally unnoticed. If there's one thing you can learn from this is, it is don't hint to a man. If you have something to say, say it, and your future men friends won't get the impression that you are expecting them to be mind readers.
You say that you are extremely possessive of him. That raises alarm bells to me. And is a possibly risky position to be in with someone you've not even got to know properly. Are you absolutely sure this isn't a crush on your side ?
Maybe you should cool it for a bit, and then if you are still interested, tell him so. Make the running yourself. But make sure you know this potential relationship is right given the age difference appears to be between a rather young girl and a mature man. I'm not knowing anything apart from what you have told us so far, but I'm not 100% comfortable about it.