Set: In the past. Dean is 14 and Sam is 10 so he doesn't understand much about the hunting. (Based on the song: Do You Want To Build A Snowman from Frozen)
John Winchester was out on a hunt, leaving Dean to look after Sam and had given him one simple rule: Don't go outside. After he had left, Dean stayed in his and Sam's room, while Sam was watching the outside world as it started to snow. The young Winchester boy knocked on his brother's door eagerly.
"Do you want to build a snowman? Come on let's go and play! I never see you anymore, come out the door it's like you've gone away. We used to best buddies and not we're not. I wish you would tell me why! Do you want to build a snowman? It doesn't have to be a snowman"
"Go away Sammy"
"Okay bye" Sam dragged his feet and made his way outside, Dean opened the bedroom door and looked down the hall to see the front door open. He ran out after his brother and saw Sam attempting to make a snowman. The older Winchester quickly made a snowball and directed it at Sam's head.
"Sammy, what are you doing? Dad said not to go outside!" Dean grabbed his brothers hand and dragged him back inside closing the door behind them and going back to his room.
Set: After John dies.
Dean had locked himself in his room, sitting with his back against the door and his head in his hands. He had lost his Father and now all he had was Sam. Sam knocked on the door and sat down with his back against it.
"Dean? I know you're in there. People are asking where you've been, they say have courage and I'm trying to. I'm right out here for you just let me in. We only have each other. It's just you and me, what are we going to do? Do you want to build a snowman?" Sam's voice cracked a little as he spoke, with no idea that at the other side of the door, Dean was crying into his hands.