Best Man
Robb's brooding bastard brother. He's often a thorn in Robb's side, but Robb loves him despite his low birth.
Groomsman
Theon is not thrilled that he wasn't chosen as best man. Granted, he did betray Robb to win his father's favor and "kill" Robb's youngest brothers, but he's a troubled lad!
Maid of Honor
Though Sansa has never met her sister-in-law, she wholeheartedly believes in love and the sanctity of marriage. Whether she will continue to feel this sentiment in her later years is yet to be seen...