Clothing optional family resort stories
Your requirement is a minor part of this million word tale.
https://storiesonline.net/library/storyInfo.php?id=29898
There's a few mostly written by lordshipmayhem in these sets: https://storiesonline.net/universe/642/manatee-bay and https://storiesonline.net/universe/558/the-competition.
Bare Assets by Dual Writer. Not sure it was a resort; I think more like an "adult community".