What to put down as monthly payment for on a car loan application?

I own a home with my life long partner of 13 years and we are both on the mortgage and deed of the home. I am applying for car loans now. I want to know do I put our whole mortgage payment down solely on monthly expenses or do divide it in half. Since he pays 50 percent of everything. I am afraid if I list the whole amounts of everything it will look like I can not afford it. When in reality we both own our home and he really pays for it.
Added (1). This for a car loan, when they ask you what is your monthly debts.

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