My question involves divorce in the State of: California

When me and my spouse decided to buy a home, my father helped us with a down payment of $90,000.

I have a written/verbal contract with my father that this amount is to be paid back in full if/when the home is sold.

We are now selling the home and splitting the return 50/50 as a part of the divorce.

My question is this-- Now that we are in the process of divorce, is my spouse responsible for their portion of the down payment loan ($45,000)? Or am I required to pay the $90,000 in full by myself?

Any information regarding this issue and how to approach it would be greatly appreciated. Thank you in advance.