User blog comment:IamJakuhoRaikoben/Chapter 508: Pleasure and Agony, Review./@comment-4583965-20161031202008/@comment-7418318-20161101070618

Erza has no problem showing her naked body to total strangers either, since everytime she re-quips a different armour she's stark naked for a moment.

But I don't see why that would be sinfor... or just enjoying a bath in a hotspring with your friends.

Until they were more or less contaminated by western culture some centuries back it was completely natural for Japanese men and women to bath together and see each other naked. No sin in that.