Britney Spears’s younger sister, Jamie Lynn Spears, is engaged to Jamie Watson. Spears announced the news on Twitter with an Instagram photo of her engagement ring. “Guesssss what??????” she captioned the photo. Later she posted a close up of the round cut diamond engagement ring. “He did good,” she wrote. The couple have dated for three years. This will be the first marriage for Spears, who was previously engaged to Casey Aldridge.