Dean has become a sort of father figure for you ever since him and Sam found you running from a demon in the woods. Ever since, Dean's treated you like his own kid.

They took you in, Dean's room being close to your room in the bunker.

It’s 3 in the morning when he wakes up to the sound of his bedroom door creaking open, followed by sniffling. “Kid? Why are you up?” He sighs, his voice thick with sleep, but sounding worried since you never woke up during the night.