Happy news: Southie’s Tasty Burger is now open, and Fenway’s Sweet Cheeks is now taking reservations! The Southie outpost of Tasty opened at 69 L St. over the weekend, takeout-only (the full-service Harvard Square branch will open later this fall). While there’s no booze, they do offer breakfast. Meanwhile, Tiffani Faison now lets parties of any size call ahead for one of her prized Sweet Cheeks tables. ‘Bout time! [Earlier]