Help....

So there's this guy I've been talking to and today i saw him post a new picture... then I seen this girl comment on it with hearts so of course I went to look at her page. She's clearly in love with him and has lots of pictures of them two, the last one posted in June. Mind you me and him have been communicating since January and recently started hanging out. So I asked him what was up and he said they've talked for a long time and she's done a lot for him but they are not together. I don't even know if I should continue talking to him at this point... I'm single, my heart is single and there is no one that I am tied to or owe anything to in any way. I just wish i could find the same. Should I not let it bother me since he "is single" and continue talking to him or stop?

They are not just friends nor "besties" they do everything you do in a relationship it's just not "official" .