Re: A man who professes he will never marry...
I think the only solution is for you to sit down and talk to him about it, accepting that he probably IS dead serious and that it may end your relationship - but surely better sooner than later? I mean, if he's dead against marriage then one of you will have to make a sacrifice, which is probably going to lead to resentment etc (e.g. failed marriage if it happens, or you miserable if it never will).
I think that hoping he'll change his mind is a bit foolish given his age - if he was 20something then I'd say hope away, but at 39 it seems his decision will probably not change.