Erykah Badu is singing the blues after unintentionally sparking Obama drama on social media. The soulful Grammy Award winner took to Twitter seeking the former first family’s forgiveness for being a "terrible guest" by posting pictures and videos of Barack Obama’s massive 60th birthday party in Martha’s Vineyard on Aug. 7. "Mr. And Mrs. Obama, Please forgive me 4 being the ‘terrible guest’ at such a sacred event for your family," Badu, 50, real name Erica Wright, tweeted Thursday. The "Window Seat" singer’s unauthorized social media posts showed the birthday boy with wife Michelle, 57, dancing mask-free among the hundreds...