I might not handle this situation the way most people would, but my gut instinct would be to tell the guy — if you’re interested in these other women, go pursue them. Let’s call a moratorium on our relationship of, say, 6 months. You move out. Go get a studio.
At the end of that time, let’s meet for coffee and talk. If I’m still free (if I haven’t met anyone during the 6 months) and if you’ve worked the longing out of your system enough that you have decided I really am the one for you — then we can get back together with the expectation that we are going to get married. Not necessarily immediately, but we need to hit whatever milestones make sense to move in that direction.
If, however, 6 months pass and things don’t work out — that’s fine. Maybe you (the guy) will discover that you’d really rather be with someone else. Maybe I’ll meet someone else or discover that, even if I haven’t, I don’t really want to be with you. That’s fine too. If that happens, we take whatever steps we need to as far as dividing up any remaining stuff, etc.
Now, in real life I don’t know if I would be as cut and dried about this. But at some point you have to fish or cut bait…