Why hasn't he asked me out yet?

we've known eachother for ten years and have liked eachoother since we were itty bitty we've been tlkn/flirting for a year now but he hasn't officially asked me out . We act like a couple dates, kiss , and cutesy stuff but idk if were bf gf or not I've kinda hinted at him by asking him what I should tell ppl he is to me but he changes the subject what does this mean? My best friend asked him why he hasn't done it and he told her next time he saw me he would.. And he didn't is he ever gonna ask? Should I ume we are? Or is this just a lost cause?