Hi, I had read your posts previously and I'm glad you have worked out most things.
I would definitely protect your interests. If I remember right, you were carrying most of the financial burden at this point, which would be of concern to me.
However, my opinion is that being married should not automatically give you a 50% interest in the property. I think the following may help you determine how you might deal with this possibility ownership:
1. How much equity does he have in the property?
2. How much equity did he have before this downturn in the economy?
3. How long has he had his property? In other words, how much money has he put into his payments, upkeep, repairs, etc. over time?
I'm in a situation similar to your fiance's; I have remarried and I am the sole owner of my property. I have been divorced before and as a single person I scrimped and saved, going without luxuries and wants for many years in order to pay my mortgage/taxes/insurance and to make about $100,000 of improvements in my property. I still pay the mortgage and the household bills. I could not just hand over any portion of this property, at least until I begin to feel his contribution has been equivalent. I have a huge investment of planning, self-discipline, do-it-yourselfing, and money here. I take a lot of pride in what I have done. I would not feel it was fair to give it away to anyone, not even someone I wanted to spend my future with.
My husband doesn't agree with my decision to keep this only in my name, by the way, but on the other hand, he has never offered to put any of his retirement funds in my name. I do however appreciate many of the investments, particularly in time and upkeep, that he has made in our home. Please understand that I see this as our home, even if it is in my name.
If you are feeling a little unappreciated because of his request, you could think about it this way: if you had an investment into which you had sunk thousands (maybe hundreds of thousands) of dollars, would you feel okay with letting him take instant ownership in that investment?
If you are paying the household expenses or a portion of them, you may want to work out an agreement whereby you slowly gain a percentage of ownership.
I know I have only one perspective and others may have another. Good luck with it!