Help the hungry roommate ask a polite question about borrowing an appliance.

Hey, ___ the waffle maker tomorrow morning? If not, I'd love to make a massive breakfast.

The correct answer is will you be using.

The future continuous is often used to ask politely about someone's plans, especially when we want to ask for a favor or borrow something. It sounds less direct and more polite than "Are you going to use...?" or "Will you use...?".