Based on Season 4, Episode 2 "Are You There God? It's Me, Dean Winchester"

Prompt: "You know how little siblings are, right? How they'll do anything for you?" – Meg

From the minute Sam had found out the truth about demons, he had developed a bit of a worship complex in regards to his big brother. And Dean, being Dean, had done little to discourage it.

It had always been his job to look after Sam – he had never expected recognition or reward. From the second Sam had been thrust into his arms, taking care of him had been his duty: his one life's purpose.

But suddenly he would come back from making out with some chick after school to find out that Sam had made him dinner – that the boy was sitting there, eyes wide open in anticipation of whatever story was to come; listening with rapt attention to whatever Dean had to say.

Whether hunting or dating, Sam took Dean's word as gospel. He stayed up late every night going over the details again and again until he had got them just right. Flicked through Dad's journal until he could cross-reference in a heartbeat: anything to make Dean proud.

And from the second the physical training had started, every move Sam made was to impress Dean. He certainly didn't do it for his Dad's sake – the way Sam saw it John was just using Dean to fight his war. Dean deserved more respect than that. But if Dean wanted Sam to be a good hunter then that was different. With Dean it was about protecting Sammy – keeping him alive.

In the same way that Sam was naturally apt at completing his studies, he found himself more than a willing participant in Dean's training programme: what Dean wanted, Dean got.

At this young and vulnerable age, however, Sam was yet to realise that this was in fact the last thing that Dean wanted. And as the years passed, the elder sibling realised it was too late to change anything – Sam's hero worship had indirectly put him in the line of danger and, like everything else concerning Sam, Dean felt responsible.

Only when Sam enrolled for college did Dean feel he could finally save him: Finally get him away from the monsters that haunted them.

"If you ask me to stay, I'll stay," Sam had said, those brown eyes wide again awaiting instruction. But it never came.

What Dean wanted, Dean got.