My girlfriend and I are often nude around the flat, we have both gone whole weekends nude in the past. However she doesn't know I've been to nude beaches and naturist swims. We have talked about going to a nude beach though.
The closest I ever got to 'outing' myself was when I dated a girl and I started walking around naked after my shower at night. She used to just giggle and thought it was funny. She joined me once or twice. I never spoke up about wanting to go somewhere public and enjoy being naked outside with others. Still wonder if she would've been down.