My resort is "nudity-expected", and they have an interesting guideline when it comes to going bottomless. The T-shirt cannot cover all the way below the butt.
The purpose is to deter people from using a long t-shirt to "hide." But the implication is that the pussy (or cock) has to be visible for bottomlessness to be "kosher."
I actually think it makes sense for a "nudity-expected" venue. My wife thinks it's stupid lol! I guess from her female perspective it means her pussy has to "show" no matter what she's wearing.
