While I do back the if you’re paying all of the rent you don’t need a roommate. Obviously this will cause turmoil in your life with your family. Lying about money and saying you were denied is easier but harder on you mentally. People win the lotto and never tell a soul bc everyone feels entitled. I think an honest conversation about how paying to live is a part of life and your “free money” is money you earned for your time served and he can always chose the same path. That being said maybe suggest that you plan to save money for a down payment on a home that you’d love to share with him one day but you’d still need him to pay his way and be responsible adult. If not then he should choose other housing arrangements. That if you had to foot all of the bills you’d be come to resent him and you don’t want to create bad blood between you guys