Grey's Anatomy 12x24 "Family Affair" (Season Finale) - Meredith and Maggie support Amelia on an important day; Jo reveals that she has been keeping secrets from Alex while Arizona and Callie deal with the impact of their custody arrangement. Meanwhile, Ben leaps into action to help a friend, on “Grey’s Anatomy,” Thursday, May 19th on ABC. Grey's Anatomy 12x24 Promo/Preview "Family Affair" (Season Finale). Grey's Anatomy Season 12 Episode 24 Promo. Grey's Anatomy Season 12 Season Finale Promo. Grey's Anatomy 12x24 Promo "Family Affair" (HD) Season Finale. Twitter :.