Normally, I'd say Mary Ann. But, hey it's a desert island, Thurston has his hands full, the professor has his toys, and the Skipper & Gilligan - well let's not go there.
So someone has to step up to the plate and make sure both ladies are *ahem* enjoying island life, let's say.
Ironically, the real Walt Whitman would be wholly uninterested in the entire proceedings.
The funny thing about this whole concept is that most of us have thought about this, I mean really analytically, thought about this, several times during our lives. In the real, scientific, objective, serious way that only the man-brain can achieve when approaching the metaphysics of banging fictional characters.
Point is that we have all drawn this out so far in our own heads that when it comes time to reply to a post like this we have to spend much more time thinking about what NOT to say than answering the question. Hence the short pithy replies.