Actress Katherine Heigl is so close to her GREY'S ANATOMY co-star T.R. KNIGHT, she has refused to get married without her "brother" by her side. The Knocked Up star is to wed her fiance, singer Josh Kelley, later this year (07) - but she was so adamant Knight was present at the ceremony she has planned her 23 December nuptials around his work schedule. A source tells Us Weekly, "(Knight's) a brother and a best friend to her. "She wouldn't get married without him."