Sam is in love with Dean, and Dean really does want to feel the same.
Based on this tumblr post, though I know that I am not doing it justice in the slightest.
Sam looks down, fidgets with the edge of his shirt. His ears are bright red.
“I know it’s stupid, just. Forget I said anything.”
“No no, I mean if this is something you want then we should at least talk about it, right? I mean I ought to give it a chance, anything for my little brother, you know.”
“No, Dean, I know that it isn’t... Right, or whatever, and you don’t feel the same anyway, so we can just. We can forget it, I don’t want it to change anything between us. And I mean, it’s not like I’m gonna jump you in your sleep or anything, don’t worry.” Sam’s rambling now, and Dean steps forward and lays a hand on his shoulder.
“Sam, hey man, it’s alright. We can give it a shot or whatever, if that’s what you want.”
Sam looks up at him. For a short moment there’s hope in his eyes, but when Dean looks again, all he can see is sadness.
“Dean, I don’t want you like that - you shouldn’t do that. I mean, if you felt the same, then yeah, that would be great, but you don’t, so.” He takes a deep breath, before he continues. “You shouldn’t feel like you have to do this for me. It’s not right.”
“Sam, you’re not forcing me to do anything. It’s for myself too. And hey, I’m not saying that we’re gonna have sex right now or something.” He squeezes Sam’s shoulder gently, and tries to radiate calmness. “Let’s just take it slow, yeah? We’ll, I don’t know. We’ll go out to dinner or something. Like a date.” He pauses, suddenly unsure of himself. “If you, I mean if you want to, that is.”
A hesitant smile begins to show on Sam’s face. It’s gone a second later though, and when he answers, he sounds positively heartbroken. “I would like that. I really would, but Dean.” He looks away again. Blinks a couple of times. Looks back up. “You don’t feel the same.”
It hurts to watch. Sam is fighting back tears, and Dean doesn't know what to say. Instead, he reaches out and puts his hand on Sam’s neck. His hand shakes slightly as he brushes his thumb over his brother's cheek. Sam takes a shuttering breath and leans in to the touch. Dean has never before seen his brother look so vulnerable.
“You don’t love me like I love you, so what’s the point?”
“The point is to try, Sam. I might not feel like you do right now, but who knows, it could change. And I want it to! I honestly just didn't think about it until you, uh...”
“... until I told you that I was in love with you.”
Sam sounds like it’s hurting him to say it.
Dean doesn’t break eye contact when he answers.
“Yeah. Until you told me that you were in love with me.”
When Sam doesn’t answer, he continues. “I stand by what I said. What I feel, it could change. Now that I know that this is a possibility, it could.” He pauses and flashes Sam a quick smile. “Lets go get dinner at that place we saw a couple of miles back. We can drink wine and talk about our life ambitions or whatever. And well, we’ll see what happens.”
Sam blinks again. A small smile tugs at the corners of his mouth.
Dean’s smile widens. “I want to, uh. I’d like to be this, for you. I want to feel the same, and I think that I could, maybe. If we try. I could learn to.”
Sam’s smile broadens, and there’s relief and hope, and just a little glimmer of disbelief in his eyes.
“Are you telling me that you want me to woo you?”
“I’m saying that I wouldn’t mind it if you tried.”
