Legal Question in Real Estate Law in California

Re: Joint tentant

Well, "default" wouldn't be the best description of your grounds for suit; the lender can bring an action to foreclose a loan if the borrower(s) default, but you're a co-borrower and the two of you are probably jointly and severally responsible for the loan payments. However, yes, I believe you would be able to sue your ex-boyfriend for breach of contract on an express or implied promise to pay half of the loan payments.

Such a lawsuit would have some problems of proof that each of you was supposed to pay half, and a statute of frauds problem if the agreement to share the costs wasn't in writing (you don't mention having an express agreement, either written or oral, to share the payments). If you won, he would owe you a lot of cash, and there might be a collection problem as well. Finally, he would end up remaining a co-owner with at least a theoretical right to co-possession.

So, I have two ideas for you that might be better, and they may sort of work together. I'm not saying this is necessarily a better route, but it warrants consideration:

(1) Sue for partition. A partition suit asks the court to rder the property divided between co-owners. In moder times and urban setting, this is usually done by selling the property and dividing the net proceeds after paying the loans, other liens and costs. The division doesn't have to be equal; the court will give any co-owner who has made a disproportionate contribution to costs such as mortgages, insurance, taxes and necessary maintenance a reimbursement. Further, there is no offset against you for "rent" because you lived in his "half" as well as yours. Further, you can probably arrange to be the buyer at little net cash cost, and by the time you have to buy, the 1st will be paid off and you can refinance and own the house 100%, no ex in the picture as co-owner.

(2) Also, there is a possibility you can assert a greater than 50% ownership, despite how title reads, if you paid more than 50% of the cash down payment, closing costs and deposit. A principle called "purchase money resulting trust" declares that title is presumed to follow risk money paid, not percentages shown of the deed, unless a contract shows a differnt intent or the buyers' relationship shows a gift was intended. Please contact me with details if you'd like to pursue either or both thoughts.