Today on Twitter, one 'Glee' superstar reached out to say Happy Birthday to his grandmother in a very public way. Kevin McHale hit up his 500,000+ followers to tweet a special message to Grandma Mimi, who turns 93 today! We hope Mimi has a great one. Elsewhere in the social media world, Soulja Boy, fresh out of jail, pimped his new album while JoJo enjoyed a little gym time and Pete Wentz teased fans with some naked camera action. See what your favorite pop stars were tweeting about on this gorgeous Saturday!