The children of two separate dynasties have come together to maximize their joint nepo. Bill Gates’s daughter Phoebe and Paul McCartney’s grandson Arthur Donald are dating, the computer heiress confirmed in a photo diary for Nylon magazine. “My boyfriend, Arthur, giving me a lift post-ceremony,” she captioned a photo of Donald giving her a piggyback ride at her graduation on June 15. In another image, we see the couple posing at her evening festivities. “With Arthur...