Let me rephrase my last question?

didn't think i phrased things well enough in my last question.... started seeing this guy that i've only known for a few months and we're acting like we've been going out for years but he hasn't asked me out and doesn't seem to be after a full on relationship. might be cos its too soon after his ex or is he using me? he says i mean the world to him and we are really close. i don't understand why we cant make it 'official'. i want to talk to him but i also want it to be him that says something first so i know he's ready. should i just hold on and keep being sweet?