Re: Nude tanning etiquette
Wow. That is a surprisingly interesting situation.
I don't know how you can say there is etiquette, but then again. How do these girls know you?
That would be kind of awkward if random girls decided to go tanning.
Anyway, I think your best bet would be to leave them alone. See what they intend to do. I'm thinking they might have other motives in mind if they were bold enough to ask to tan naked with you.
And have fun, of course.