Re: Naked room mate
You're not asking why he does it here,( Answer: Because it feels good for him), you're asking for a way to help him stop. (Note: Forget about his sleeping habits, they don't involve you, focus on his ambulatory style).
The answer to THAT is simple. Be direct, don't be cryptic and ask a question that you hope he'll figure out why you're asking. Something like, "Listen, I need you to stop walking around naked when I'm here". Simple, direct, to the point. Has nothing to do with your sexuality, just your feelings. And roommates, living with eachother, need to do that.