I think kids should stop seeing you naked as soon as they start giving you The Awkward Stare:
You’ll know it when you see it.
I never felt uncomfortable changing in front of my kids until I noticed them studying my every body part.
They also started pointing and saying “ewwwww!!!” so I guess that’s another red flag. Needless to say I’ve already begun kicking kids out of my room for privacy!
When should your kids no longer see you naked?
And also? Put some clothes on.