What do you make of a guy who's been dating a girl exclusively (according to him) for nearly three years, but won't put a title on it because he says he equates "boyfriend-girlfriend" with "one step from marriage", even though he claims to want to marry the girl one day?
But the elephant in the room here is the amount of time you're talking about here. Three years is a long time to be with someone and still be adamantly against a title. There's a reason for that and you need to find out why. Maybe he wants to marry you at some point in life, but he doesn't want to act like your husband now. If you don't know what that means, have an honest discussion with him about it to find out.