I don't really know what to say, but thanks for all of the awesome reviews!
All he ever wanted was his brother. He just needed to make Sammy see that without coming right out and telling him.

Dean used everything that had been made available to him, including a geeky little outcast of a kid. It was perfect, really. The boy was just like Sammy, just itching to get away. He used the kid to make a point and drive it home.

In the end, the boy and his family lived happily ever after. Dean knew he should be happy for them, but Sam still didn't seem to get the drift, so he could only be bitter. It was because of this that he knew he was selfish.