First, ask yourself whether it’s crucial. If you’re just curious, it’s probably not worth creating a schism. If it’s crucial, you could ask it in a roundabout way: what’s their religion’s position on LGBTQ issues? They might relay their own position in the process. The other question is what you’d do with the information. If this is regarding your own sexuality and they’re homophobic, would you keep it a secret? Come out anyway? Ask for a housing change? Before you do anything, I’d recommend visiting the LGBTQ-friendly folks at the Office of Student Outreach and support: http://bit.ly/LBGTQBC.