Most Helpful Guy
This is a really weird situation. I mean... He knows that you know about his proposal so I'm not sure what he's trying to do by making you wait so long in the first place. It's not really a good thing to keep anyone waiting on anything, especially a proposal. Not to mention you already know about it so really, what this special moment possibly could be? I don't really know but the fact that you know about it just makes me think he's a little clueless.
I think that it might be a good idea to talk to him about it. I think after some time the novelty of waiting kind of wears off and you end up impatient or feeling as though he didn't really want to propose at all which I take it is how you feel now. If he does want to propose to you, and he does want to marry you, then I am sure he will take your feelings to hear and will explain himself a bit better to you so that you can understand why he is doing the things the way he is doing them. :)