My son is 5 months old, it's summer and we have a paddling pool set up in the yard. My wife - who is not a nudist and isn't exactly happy with me being one - is happy for him to go in it naked. If we had him naked outside every day at some point I guess he'll say no I don't want to anymore. Why?
It's because of other people. As much as your or I have a right to show other people our goods, they have the right not to see it. Don't get me wrong, I love nudity, but just out of pure courtesy, it's best to do it on your property or in marked nudist areas. Anything other than that is honestly sexual harassment in my opinion. And that's coming from a woman who doesn't wear underwear and visits a nude beach or goes hiking nude more often than not.
It happens that when we get older our choices change and change several times. If he saw mom and dad naked he might like being naked more but he may grow out of it when he learns other people don't approve. You never know so give it time and see what happens.
Respect for others is not a factor. I'm talking about being naked in the paddling pool every day of his life, will he one day say no I don't want to anymore?
The odds of it are high. But as far as establishing a timeline; well that's hard to tell. Kids become conscious of their naked body around 2 on average. I'm no child psychologist; but they react differently to it based on personality and environmental factors. Because my daughter's Mom and I had developed a family nudist culture, my daughter sailed right through that developmental stage with no hang-ups about nudity. But in an environment where nudity is rare or non-existent outside of the paddling pool, it is very likely your kid will "opt out" sometime around that stage.