Dean's dead. In season 2 he died instead of John being able to save him. You and him used to be close friends. You may have even liked him a bit more than friends.

You were in the back, watching the funeral, separated from the rest of the people. You didn't show much emotion. You just kept your hands in your pockets and looked down, or at the coffin. Sam notices you and once the funeral is over, he decides to stay after and lurk to see what you do.