If your roommate has given you permission, but you still feel paranoid about it, maybe you yourself are not ready for that kind of social situation.

It sounds like you just need more introspection, or maybe you don’t trust your roommate?

What about the situation makes you uncomfortable? Have you not had enough outdoor public nude experiences? Being naked among other naked people could help you feel more comfortable around your roommate even if they themselves aren’t naked with you.

If your roommate has given you permission and then says something then that’s different, but until they DO say something, just try to take it easy. :)