Found this AU on Pinterest and thought I'd share it. We don't get to see a lot of the Winchesters past, especially how hard Dean had it at such a young age, so I think this helps explain why Dean acts the way he does at sometimes. Hope you enjoy! :)
August 19th, 1985
John breathed in the cool air in Shelton, Connecticut as the sky above him had cracked open, causing rain to splatter around on the ground. The night sky that was previously lit up with stars and the full moon instead was covered with dark clouds that crashed in. The Winchester breathed deeply once more, taking in what last he could of the nice air before turning back and heading into his motel room. Once John made sure the baby of the family was asleep, he'd leave the older one to watch over as he set off on his hunt. Inside, his youngest, Sammy, was curled into bed with his stuffed lion named Rucko. He was half asleep but opened his eyes slightly to see his father come in. His older son, Dean, laid on the springy couch in the corner. He looked asleep but cracked his eyes open as well to see who it was and then yawned.
John tucked the blankets closer to Sammy's neck as he smiled a bit, Sam letting out a quiet yawn himself and mumbling, "I wuv you, Daddy."
The older Winchester smiled, bending down to kiss his son and turning off the lamp that was next to Sam's bedside, "I love you too, Sammy."
John stood back up his heavy boots sounding almost inaudible against the wood as he quietly made his way to the door. He had just grabbed the doorknob when he heard his six year old, Dean's, small voice.
"I love you, Daddy."
John turned his head slightly to see the slight glistening from the bit of light outside on Dean's eyes but shook his head with disappointment and huffed deeply, "You're too old to be callin' me Daddy, Dean. Go to bed."
Dean swallowed, tearing his gaze from his father's as he bit down on his lip and paused. He then quietly answered, "...Yes, sir," and with that, John closed the door.