If you reside with BOTH parents…you are REQUIRED to put both incomes and assets on the FAFSA. REQUIRED.
It’s not a choice.
It is fraud to gain financial aid by knowingly providing incorrect information. Fraud is a CRIME. In addition to losing any financial aid you might gain…you also would likely lose your offer of admission, and be fined.
Just curious…how does your mom file her taxes?
Are your parents married? That doesn’t matter for financial aid purposes if they are living together…but there IS a question on the FAFSA about parent marital status.