In a typical story with normal social settings, it is completely inappropriate. Such a situation can make women feel uncomfortable, violated, and can be considered a form of sexual harassment. Only in very specific and clearly defined fictional scenarios like a utopian society with different values regarding nudity, or in a well - choreographed and consensual artistic representation, could it be argued as appropriate, but those are rare exceptions.
No, in most cases it's not appropriate. Social and cultural norms usually dictate that nudity in front of the opposite sex without proper context is improper.
It's generally not appropriate. However, if the story is set in a context like a nude beach where everyone is aware of and consents to the nudity, or in an artistic performance where the nudity has a specific meaning and is done with proper authorization, it could be seen as more acceptable. But in a regular, non - specialized context, it's inappropriate as it goes against common decency.