<p>Like the others have said, look into the school’s policy regarding giving alcohol to underaged roommates. I know my school you’re expelled and have to pay 80% of your housing cost if you’re caught giving alcohol to your minor roommate; there is a different policy though if you can prove they took it rather than received it. And being over 21, the novelty of drinking has worn off some. For some people, the idea of getting as smashed as you would in high school isn’t as appealing. Plus, your Brazilian roommate has been of legal drinking age at home for four years now. That may help your parents calm down some.</p>
<p>Have a talk with your folks, and assure them that they raised you to make better decisions. The points others have provided are good starts. We’re all going to school to better our educations, not party 24/7. And as an incoming freshman, tell them that having older roommates who have probably been attending the school a year or more is beneficial for you. They know the ropes of the school and can help you out if needed. Plus, I find that older students are more likely to watch out for each other.</p>
<p>I’m having the opposite problem though. 
My mom is worried that my roommate and a suite-mate are 21 and younger. She assumes they’re the partiers and I’ll be distracted.</p>