Am I been played?

I have known this guy for about 10 years (i am 17 and he is 19) we are family friends. About two years ago we started to hook-up casually (not sex!), and recently we have been talking about being more then friends. We will hang out and flirt and talk about being together, but then when he leaves i dont hear from him until he wants to hang out again (which is like once a week). He told me that he likes me and wants to be with me, but then why does he not message me?