Thanks for the info, guys. I think you are all correct that if my wife isn't hot for it ahead of time, bringing it up spur of the moment while on vacation would be a mistake. The suggestion would have to come from one of the ladies to be a consideration for my wife at this point, in which case, I can only hope and fantasize and think really positive.
It's not really my fantasy to play with the couples involved, although I wouldn't have the sense to turn it down of it were offered sincerely. I was thinking of more a same room, same partner thing. Worse, I could be being tested, like her asking me if I wanted to play with them, only to find out it was a ruse to test my faithfulness.
We did go to Little Beach about five years ago, for our twentieth; I went nude, she did not. As a total mood killer, she asked, "Is it everything Ablout that you imagined?" About that time, I got up and left.
We are going to the big island this time around, there may be some deserted beaches way south. Cross your fingers for me!