We act like we are going out but we aren't. ?

I'm 13 almost 14 if that matters. Me and this guy have been friends for 5yrs. we act like we are dating. We hug, sometimes hold hands, lean on eachother, and flirt. It's weird cause we aren't dating. For some reason we just don't. Its awkward cause he had a girlfriend a while ago yet we still flirted, so it seems like he was cheating. I don't want to ask him but it's weird. He almost kissed me once but I pushed him. Why won't he ask me? Should I tell him to stop flirting (Even though I do it to and like it)?