My brother's roommate is gay and my parents want my brother to move out. What should I do?

Sorry if I'm breaking subreddit rules with this post or my terminology. I'm not a regular here and I'm on mobile so I can't see the side bar.Three days ago my brother started college. While helping my brother move in my mom started to suspect that my brothers roommate is gay. Today my mom, dad, and I are bringing my brother some stuff he forgot at home. My mom and dad are Christians who don't approve of homosexuality. They want to see Roommate and decide if they think Roommate gay. If they think he's gay they will request that my brother move and get a new roommate.My brother is bisexual and in the closet. The roommate is gay and out of the closet. Parents worry that rooming with a gay person will make Brother gay. Brother and Roommate don't want to deny that Roommate is gay. Brother plans to use logic on Parents by arguing that Roommate is a good student who's orientation is irrelevant and getting a new dorm room would be a hassle. I am not optimistic about this strategy.Brother has a tuition scholarship and parents are paying for everything else. He has never had a job before. In high school he was very smart, but his grades suffered because he had really bad study habits, so I worry that he can't maintain a job and college at the same time.I know this isn't about me, but I might as well disclose my slight conflict of interest. I'm straight and graduated college a year ago, but had depression and no sense of direction career wise. So I've been living at home rent free while my parents pay for my food, medication, therapy, etc. I have a really close relationship with my mom, who kind of relies on me for coping with her own depression. My dad is frustrated with my lack of career and has threatened before to kick me out. We have never talked about homosexuality at home, so I don't know how far my parents are willing to go with this. I'm ashamed to say that I don't know how far I'm willing to go to oppose them.Do you have any advice for what I or Brother should do? Right now Parents and I are driving and will arrive at Brothers college in an hour. No pressure folks.