Dean had just gotten back from a solo hunting trip that he had decided to go on alone instead of taking you or Sam with him.

Dean came back to the bunker a couple of minutes before midnight and was injured. He went to find his little brother first, but he found him sound asleep and shuts Sam’s bedroom door.

Dean was about to go to his room; but he noticed that the light was still on in your room, he went to your bedroom. Knocks on the door and waits to see if you were still up or not.