Technically no, you must pay for care so that both spouses can work or attend school full time.
However, the way the form is structured, it relies on you to state that the expenses are qualified, and only looks for earned income from both spouses. (Same for the certification you are required to sign to get reimbursement from the FSA provider.) If you claim the expenses are qualified, there isn't any automatic way to get caught, other than an actual audit.
