Claiming Adult Dependents on SSI

A family member who I rent a room from has been claiming me as a dependent. (I am on SSI). This is frustrating because the individual does not pay for my expenses. I pay them above the rent SS says I should . Whenever I can’t afford something, I always make payments to the individual until the item is paid off. They do not pay for 50% of my expenses I pay them all. The individual could not provide proof otherwise. Is what they are doing legal?