After 4.5 years together, it's totally fair to want to figure out where you guys actually stand! But before you have that big formal conversation everyone else is talking about, maybe first try to understand what's really holding him back - is he worried about money, does he have doubts about you two, or is he just dragging his feet because he can't be bothered? Both approaches can work, but understanding what's actually blocking him first is less aggressive and you'll know whether you really need to push or if it's just a timing thing. If after that he still won't give you anything concrete, then yeah, that's when you need to have the real talk!