I'll be nekkid at the back of the house, but not in the front room with curtains open, like my other half (though there is a considerable mass of shrubbery between us and the street!)
My parents hung about naked a lot in the mornings... if a friend unexpectedly stayed over after a night out when I was a teenager I'd have to make it quite clear to my parents that someone else was going to get up soon.
I don't think any of my mates saw my parents nuddy, although gsv did once chance upon my dad talking on the phone, with nothing on! The lady who cleans their house once a week has just become quite immune to running in to them when they're naked at home now and then.