Legal Question in Real Estate Law in California

To the lender, you are still equally liable on the loan. That he is making the mortgage payments does not negate your responsibility. While you still are on somewhat friendly terms you need to work out an agreement with the ex as to ownership, re-financing without you on the new loan, etc.

Mr. Shers' advice is good provided (a) you are on speaking terms, and (b) the ex has some flexibility that he's willing to use on your behalf.

More likely than not, however, your ex either has limited financial "wiggle room" to refinance and take you off title, given that the property is upside down, limited willingness to come to your aid, or both.

That being the case, you have a "do nothing" option and a "legal action" option. Under the do-nothing option, you cross your fingers and hope he either makes the payments until the house once again has some positive net equity, or that, if he defaults, the trustee sells the property and the only side effect is a hit to your credit rating. It is rather rare for a lender to decide to foreclose via a court proceeding (judicial foreclosure) and thus to get a judgment for any deficiency when the house is sold. They can't do a judicial foreclosure if the loan is a purchase-money note and deed of trust.

Under the "legal action" option, you could sue for "partition" of the property. In a partition action, an unhappy co-owner asks the court to require the property to be divided among the co-owners. This sued to be done (when we lived on farms) by subdivision, but in more recent times, nearly all partition is done by sale and dividing the net proceeds. When property is upside down, there are no net proceeds, of course, and the plaintiff is stuck with legal bills and various costs. Probably not your best option at present.