When Ruby fell to the ground, Dean just stood, looking into his brother sad and guilty eyes. And when the "I'm sorry," came almost as a whisper from Sam, he new he had fail as a brother. He should have been there to protect Sam, but instead he had been with those jerks, who called themselves angels.
When Dean didn't know what to say he just looked deeper into his baby brother's eyes, and saw the same eyes, looking back at him, he always had seen and loved.
It was these eyes Dean saw the first time he ever saw his baby brother. Dean was 4, and he's father had come, picked him up, after Dean had spend the night at the neighbours, taken him to hospital to visit his mother. When they had arrived, Dean knew he was going to see a little baby they claimed was his little brother, and of course he was exited. But nothing could ever replace the feeling he got when he came in to his mother, who was holding a little baby, and when his dad had pulled him up, to sit beside his mother and she had handled the baby over to Dean, so he could hold him. The feeling when he held him and the baby's big hazel eyes looked up at him was unimaginable.
It was these eyes Dean had seen smile, around 5 weeks after they had come home from the hospital, when he laid on the floor, on a blanket, with Sam, (they were going to call him Samuel, but they were just calling him by the nicknames Sam or Sammy, and Dean was proud 'cause he was the one who got to decide what the name should be), on his back, playing with a rattle he was holding in his hand, and Dean laying beside him, on his stomach so he could see his brother, and when Sam had dropped the rattle, Dean had given Sam the rattle back, smiled and then tickled Sammy on his belly. It was then Sam had given Dean his first smile, and when Dean had looked into Sam's smiling eyes, he had got the warmest feeling inside.
I was these eyes Dean had seen full of horror, when he had been around 10, and Sam 6, and dad had been out hunting. Dean had woken up by someone pulling in his arm, when he had opened his eyes he had seen Sam standing, tears streaming down his cheek, eyes full of horror, and when Dean had asked him what it was, Sam had answered he had had a nightmare:
"I-it was a monster, who came and took you away so I was all alone," Sam had said, as even more tears came down his cheeks.
As Dean pulled Sam into a hug, he had explained, that monsters wasn't real, and he would never leave Sam, and as Sam had calmed down, he had pulled himself up under Dean's carpet, and rested his head on Dean's shoulder. Then he had looked up at Dean, with big, hopeful eyes, asking if he could stay there, just for the night, and when Dean had looked into the eyes, he had just pulled the carpet a little father up over Sam's body, and stayed up till he knew Sam was a sleep, before he fell asleep himself.
It was these eyes Dean saw full of joy, the day Sam came home from school with his first A, calling through the motel room to find Dean and tell him that it was the test Dean had helped preparing to, wanting to see joy in Dean's eyes too. And before Dean had had a chance to answer, and congratulate, Sam almost slapped his arms around Dean, embracing him in a big hug, thanking him, and as Dean gently pushed Sam away, trying to tell him he wasn't the one who had done the test, he saw into those big hazel eyes, seeing Sam knew what he was going to say, but Sam still meant what he had said anyway.
It was these eyes Dean had looked in after every damn hunt, seeing the joy when it went good, the fear when something went wrong, the protection when Dean had been hurt, and the pain when Sam had been hurt. Seeing the horror after every nightmare Sam had had, the disappointment every time there father 'ditched' him (though it wasn't deliberately), and it was here Dean would see the sadness in his eyes when he would go to Dean for comfort. In these eyes Dean could see a life he would never live without, the only eyes he would kill for and die for. Hell, hadn't he already done that?
And it was right then, as Dean looked into his brothers eyes, he realised that all this was gonna be okay, it might take some time, and a lot of explanations, but as long as his baby brother was by his side, and nothing would never tear them apart, it was all gonna be okay.
Before Dean could say anything, the light streamed up from Lucifer's 'grave', and all he new was they had to get away
"Sammy, let's go!" Dean said and grabbed Sam's arm, but Sam just stood, grabbed Dean's arm too, holding him back and said:
"Dean… He's coming."
As the light embraced them, all Dean did was holding on to the only person that mattered to him, the only person he really cared for and knew cared for him, the only person with eyes, that could reflect Dean's life.