Asset Protection from committed intimate relationship

[Robert Miller]

I've been with my girlfriend for 3 years, and living together for 2 year in a rental home, sharing expenses, but not bank accounts.  I recently purchased a home which we both moved into, and she is now paying me rent.  The property I purchased has $100 thousand dollars in equity.  In the event we break up, how do I best protect my asset.  

Does anyone have information or experience with "commited, intimate relationships"?