I think there is a difference between people who already are naturists themselves and want to introduce it to a new partner and people who aren't yet naturists but are very willing to try it.
If the person isn't yet a naturist, the best way is simply saying to the new partner that he or she always wanted to try a nude beach. If the other seems reluctant, he or she may simply ask if they would mind them being naked with the premisse that he or she wouldn't need to be. Most people I know would agree going to a nude beach with the partner if disrobing themselves isn't mandatory.
For someone who already is a naturist, I would bring that subject as early in the relationship as possible. As in "I've been going to nude beaches many times before and I would love that you would consider going with me". The same situation, not necessary for he or she to undress.
The real difference between those two situations is that the first one isn't necessarily hiding something whereas the second, if retaining the information for more than necessary, is.
Edit: I don't think anyone should have to give up anything one enjoys of this nature for a partner. I think it's beyond what can be asked in a relationship.
This post was edited by
Vitor & Fernanda at December 6, 2021 3:57 PM GMT