He's given you the answer, but I do understand it's difficult to not latch on to what seems confusing and not consistent on his part.

You're trying to find anything possible in order to get him to say things he won't. He's not worth this kind of strife for you. I'm sure there are things you truly like about him, but he's a flake and he knows how you feel and that's a comfort for him, but does nothing for you. He should be very clear, but he won't, because he wants all the cake.

I would try to not bring up anything about any of his ex whatever's, because it reduces you. If he were to say what you want him to say, it doesn't sound like it would progress in a healthy manner. You would feel some elation for a short period of time, but, trust me, everything else would still be there and you would ruminate about it.

Be less available to him in every way. Test yourself a bit.