Hi Bling
As I said to you – your fiancé does not conform to the usual CG but his behaviour is that of a CG.  
I’m afraid that thinking a man is ‘a good man at heart’ does not preclude him from being less than good.   He has gambled with his home and now he thinks that you can pick up the pieces which doesn’t seem right to me.
I think you require legal advice.   From what you say he is not in a position to sue you for anything and the mere fact that he threatened you with such action is not acceptable behaviour.   It certainly is not, in my opinion, a good basis for a relationship.
As I said last night I cannot tell you what to do.   Having listened to you – I know that if it was me I would not let this man move in to my house permanently.  
I don’t know what State you live in but I have read many ***** that couples in some States are liable for the debts of each other – you do not deserve to have your security you have built up for yourself, threatened.  
I believe it would be good for you to take a step back in this relationship – I think that, that is what you wanted to do which is why you came on this site.   I think you are not sure of the steps to take to remove yourself gently.   I accept that you say you love him and love is often what gets in the way of us doing the right thing for ourselves.   In my opinion, ***** you, or even suggesting it, is not the act of a loving man.  
Please check on your legal position.   Put your mind at rest about the ***** suggestions.   I find them ludicrous but I believe you should hear it from a legal representative.   Make sure that you can, if you wish, rescind your offer of a home without come-back on you.  
It is always easier to let someone in to your home, who is seeking enablement than it is to get them out once they are in.  
From what you have said, this man is extremely manipulative.
I look forward to hearing from you further