I think you are on the right track...If you read my first post about this, you'll notice that what you wrote is not much different from what I wrote.
At the risk of stating the obvious, to wear a swimsuit one has first to have one...
As a kid, I saw multiple times boys, young and even grown men bathing nude in the rivers (never on the beach, though)...some probably still do...The main reason you and I already know...
