It was a mother-daughter reunion on the latest episode of Glee as Tony-winning actress Carol Burnett guest starred as Sue Sylvester's oft-mentioned but never seen Nazi-hunting mother, Doris. While she may not have approved of Sue's decision to marry herself (!), Burnett's character still wanted to sing at her daughter's wedding. Even if Sue remained upset with her mother for disappearing so frequently throughout her upbringing, Doris hoped to help Sue understand her past decisions courtesy of a Tony-winning Broadway classic. With the help of Wonderful Town's "Ohio", the hilarious duo switched to their serious side for a duet. Take a look!