Nudist cruise with my sister Karen

My wife and I booked a cruise in 2017 for 14 days but she got sick and couldn’t travel anymore. Instead of cancelling my wife suggests I go with my sister Karen who had never taken a cruise. It was not a problem sharing the same cabin because we are nudist both. Karen had been divorced for 2 years. My wife told me that if I had the chance to fuck her not to hesitate. What could happen happened. My sister tasted as much as I did. Karen and I made a number of nudist friends, including Jennifer, who has the same name as my wife. Karen posted her photos on several sites.