Legal Question in Real Estate Law in California

You should try to get this property situation under control with written agreements. As a 50% co-owner, you are basically responsible for half of the expenses, and entitled to half of the third-party rental income. However, neither co-owner is entitled to rent from the other for the other's occupancy and use of the property. Also, don't confuse loan obligation with ownership. These are separate concepts. You can be a borrower without being an owner, and vice-versa.