Leonardo DiCaprio, Kate Winslet, and Billy Zane had a Titanic reunion of epic proportions for a charity auction in St.-Tropez, France, on Wednesday. Not only did Leo and Kate share a sweet embrace on stage, but Billy also posted a photo of the trio on Instagram, paying tribute to their philanthrophic efforts with his caption, writing, "Gangs back together. Now we're saving icebergs. Go figure." It was announced earlier this week that Kate and Leo would be auctioning off a private dinner with the two of them to one lucky fan for the Leonardo DiCaprio Foundation, which will benefit a GoFundMe campaign that aims to help a young mother in the UK pay for her cancer treatment.