You and Derek are siblings, but you heard he got married to a woman called addison montgomery, years later your working as a surgon and you knew about adidson cheating on Derek and once again you took Derek's side. You knew Derek loved meredith, but you saw addison walk in and snatch Derek away as if he was a prize. And of course Derek chose addison over meredith, this time you chose meredith's side.

Addison came to you and meredith "hey, it's great to finally see you again. Your all grown up."