Page 2 of 3Another reason Bobby has such a different relationship with Sam and Dean is Bobby didn't have to raise these boys, didn't have to put up with teenager Sam or toddler Dean. Surely he was around during those times, but it's not the same thing as living with a person every day. I mean, look at how angsty Sam is as an adult. As a teen, he must have been a nightmare. And you just know that Dean was one of those kids who puts everything in their mouth that can possibly fit in there. John and Mary probably knew the number for poison control by heart. Bobby got to be the gruff but loving uncle to these two, a wholly different adult presence than what they were used to with John.
In the aftermath of John's death, it makes perfect sense that Sam and Dean would turn to Bobby for support, emotional and physical. They stay at his house for a few weeks at least, and we aren't shown it but he must have tried to help them in any other way he thought would work. It must have been devastating for him to see how upset they were and not be able to do anything about it because they just weren't that close yet, and Sam and especially Dean just weren't in the right frame of mind to accept his help.
I do think, though, that it was during these weeks when Bobby really learned what kind of men Sam and Dean had become and figured out just what kind of relationship each of them needed. Because we all know that Bobby loves both Sam and Dean with all his heart, loves them like they were his own sons. But as much as that is true, he has very a different relationship with each of them based on what they need from him. And this is absolutely my favorite thing about Bobby: he took the time to figure out what kind of relationship Sam needed versus what Dean needed and acted accordingly. He didn't try to mold them into what he thought they should be, didn't try to make them change their behavior to accommodate him. He let them be themselves, offering guidance and support to each in the way they needed it most.
Growing up, the person Sam looked to for reassurance and support, for everything, really, was Dean. John wasn't around very much, leaving the boys alone for days at a time. Dean was always there for Sam, and parented him just as much, if not more, than John did. Sam just isn't used to looking to his father or father-figure for anything. He had Dean to tend to him and protect him, and Dean was always there for him. So with Sam, Bobby is more hands-off. Sam just doesn't have that need for approval or the need to be needed that Dean does. So, Sam's relationship with Bobby feels more like one of equals than like a father/son relationship. Sam knows Bobby will always help him whenever he needs it, but he just doesn't need Bobby like Dean does.
Nowhere is this fact more evident than when Sam cuts Bobby out of his life after Dean goes to hell. Dean was the strongest influence in Sam's life, and when that influence is gone, Sam is set adrift. Because he was never in the mind-set to look towards the older adults in his life for support and guidance, he ignores Bobby's attempts to contact him and strikes out on his own, trusting to his own judgment to see him through his grief. Ruby exploits this, of course, and Sam starts on his slippery slope to demon-blood addiction.
Now, even though Sam did not want to be found and was probably actively hiding his activities from Bobby just like would from Dean, for fear of rejection, Bobby is an excellent hunter in his own right and could have found Sam if he really wanted to. But Bobby knows that Sam is more independent than Dean, knows that Sam will make contact again when he's ready. Notice, too, that although Bobby could have certainly used Sam's presence and support while he was dealing with the pain of Dean's death, he never once tried to use that against Sam to force contact with him.
What Sam needs the most from Bobby is for him to just be there for Sam when he needs him. That's why when the demon possessed Bobby in "Sympathy for the Devil," the demon knew that the most effective thing it could say to Sam to hurt him was "I want you to lose my number." He didn't say, "I don't want to see you again" or " stay away from me." He specifically told him to lose his number, to not contact him anymore for any help or information or anything. Sam was naturally crushed by this, but he was blaming himself for starting the apocalypse and didn't expect anything better. He was hoping Bobby could forgive him, could see past what he had done, but he didn't expect forgiveness. That's why the scene at the end of the episode when Bobby is in the hospital was so spectacular. Sam obviously hadn't broached the subject again and was going to respect Bobby's request and leave him alone. But Bobby reached out to him, told him exactly what he needed to hear: "I ain't cutting you out, boy. Not ever." And Sam is just so, so relieved to hear him say that.
Bobby's relationship with Dean is, again, shaped by how Dean interacted with his father when he was growing up. We've come to know Dean as a brash, charming, sociable, at times intense man whose fly-by-the-seat-of-his-pants attitude and instinctive attitude towards hunting are in sharp contrast with the more cerebral approach of his brother. Dean is fun and sweet and deeply insecure. At least, he is when he's by himself or when he's with Sam. As soon as John shows up, Dean transforms into a completely different person. He tenses up, quiets down, and just waits for this father to give him instructions or orders to follow. He's not Dean around his father. He's the Dean he thinks his father wants him to be. He does what he's told without question and trusts his father empirically. In contrast, when Dean is around Bobby, he is completely himself. This is the most important part of their relationship, I think: Dean can just be Dean around Bobby, and he knows that Bobby loves him just as he is.
Bobby also realizes that Dean is just more needy than Sam when it comes to his family, more reliant on their affection and their approval. Dean's never been very comfortable with people singling him out with any kind of attention, good or bad, so Bobby often has to find more subtle ways to show Dean how much he means to him. Mouthing off is something Dean is good at, so Bobby teases him right back, and their banter is wonderfully affectionate. Can you imagine Dean doing something like that with John? He looked like he was going to throw up the few times he contradicted John and expressed his own opinion.
Bobby knows a lot of hunters and surely must know someone who lives close enough to contact in times of emergency. But he has Dean listed as his emergency contact partly because he knows that Dean will drop everything if Bobby is in trouble and partly because he knows this will make Dean feel needed, feel like an important part of Bobby's life. And he is an important part of Bobby's life, as we've seen time and time again.
The best example of just how important Dean is to Bobby is in "All Hell Breaks Loose II," starting when Dean brings a reincarnated Sam to Bobby's house and continuing through Bobby's rant at Dean about his deal. As soon as Sam and Dean show up on Bobby's doorstep, Bobby just knows that Dean did something monumentally stupid to get Sam back. The knowing looks he keeps shooting Dean are woeful, and Dean can't manage to look him in the eyes. Sam remains blissfully unaware throughout the whole exchange, but you can just see that Bobby is trying to figure out some way to get Dean alone so he can rip into him. He's happy to see Sam alive again, of course, but he's extremely leery of what it cost Dean.
And rightfully so, as he finds out in the next scene, and it's all kinds of heartbreaking. Bobby is just so angry and upset at Dean for making the deal, for not valuing his own life at all. He just hates that Dean has so little regard for himself when he has so much regard for Dean. And I just love that he's grasping at his jacket and shaking him, trying to physically jar some sense into him. And, oh, when he puts his hand on Dean's face and just sort of gives in? That right there is Bobby saying, "I hate that you did this, but I know how much you love your brother, how you'd do anything for him. So I'm here for you, no matter what happens next."
Bobby gets just as much out of the relationship as they boys do. He doesn't have any children of his own, so they're the sons he never had. They give him a sense of purpose, a higher meaning to his life than just being a hunter. As many times as Bobby has saved their lives, they have saved his, too. Sometimes Sam and Dean take him for granted, but he never holds it against them. He can't hold a grudge because he needs them just as much as they need him. But the best thing about their relationship, the reason why Bobby has become so important to them and why he's like a father to them, is that their faith in him has always been rewarded. He has never let them down when they needed him, has always been there for the boys, and always will be for as long as he's able.