Sam was in a deep sleep. He didn't hear the door opening, and the trespasser walked in like a ghost. Castiel stands there watching Sam sleep. He never watched Dean, he respected Dean's privacy. Plus he couldn't tell him how he really felt. He read the stories online. Once you cross that line, there's no coming back. So he watched Sam instead. Jack was okay, Castiel already tucked him in after reading him a story. Jack was a adult, but still a innocent child.
Wonder what Sam was dreaming about. He had this small smile on his face and was breathing softly. He could see his mind, but he refused to. He just smiled at him and closed the door. Tomorrow is another day. Goodnight Sam.