My ficlet for the episode is focused on clothes, strangely enough. It's gen, unless you already find Sam devoting any of his precious headspace to Dean's clothing too slashy. I'm greatly indebted to hells_half_acre's brilliant clothing index and Superwiki's costumes post.
Written for misplaced_ad, because she's awesome and celebrated her birthday this week.

Unbetaed, so apologies for any mistakes.

About A Brother

Sam thought he'd already seen Dean in pretty much any outfit known to man when his brother proved him wrong, turning up on his doorstep looking like a Justin Bieber twin.

After all, he's seen Dean wearing a game warden uniform and a fireman overall; seen him proudly don an – as it turned out – not historically accurate cowboy outfit; seen him LARP as the Queen of Moondoor's handmaiden; seen him looking cute and cocky and way too comfortable in his orange prison jumpsuit; seen him pose as an FBI agent over and over in the same cheap suits and drab ties, usually grudgingly; seen him sport a ridiculous hairnet and, on one memorable occasion, a pair of red gym shorts. Heck, he's even seen Dean try on a pair of pink silk panties once that belonged to one of his girlfriends, though that's not something Sam's ever going to mention. He likes his nose the way it is, thank you very much.

What's more and possibly worse, he's seen Dean come back from Hell, dressed in a dun henley and tan shirt of Bobby's, looking more like a stranger or a specter than anything else. As soon as he got over the initial shock of the reunion, Sam selected some of his own clothes for Dean to wear – a light plaid shirt as well as his brown corduroy jacket – but that didn't really make things better. When Dean emerged from the bathroom, changed, his forehead pale and covered in sweat, muttering something about freakishly long limbs, Sam had to blink several times. His clothes were too big for Dean, especially the sleeves, and Sam tried hard to pretend that this was all that was wrong and changed.

Of course soon enough he'd been forced to give up that happy illusion. He had to acknowledge that his brother was walking around in a stranger's body, his skin smooth and unmarred save for the glaring red handprint on his shoulder. Even the big, messy scar on Dean's thigh, a relic from the first time Sam had to stitch him together, was gone.

Sam remembers staring at his brother's leg and wondering if he was supposed to forget now how Dean had talked his twelve-year-old self through the process, crying and swearing; how Dean had passed out afterwards and Sam hadn't been able to stop shaking, desperately trying to come to terms with a world in which monsters and ordinary humans likewise threatened to tear their family apart, so that Sam had to take a needle to his brother's leg and make him scream instead of calling 911. He'd gaped at his brother's unmarked skin until Dean cuffed his head and called him a baby.

It took Sam a while to figure out that simply because they were invisible didn't mean they weren't there - the scars of twenty-nine years on earth and forty years in Hell.

It took Sam even longer to get used to him again.

If you ask Sam, that should have been the undisputable highlight of the freak show of their lives. But it's not like anyone out there in this big, bad universe has ever really given a damn about what Sam wants, so instead here they are, with Dean trapped inside his fourteen-year-old body thanks to some sick flower magic.

Sam doesn't know what's worse, the cap or the Underoos.

What bothers him the most, is how this version of Dean looks nothing like the teenager Sam remembers. It's not just the clothes. Obviously Dean never wore hoodies and baseball caps, he donned Dad's leather jacket and looked immensely cool and grown-up. And that's just the thing, isn't it? To Sam, Dean was never so small, so childlike, so… pubertal. Okay, maybe that's due to Sam's embarrassing hero complex at the time, but he doesn't recollect Dean ever experiencing the horrible mood swings, the confusing horniness and the vague unease of not fitting inside his own body that Sam suffered from in his teens. From Sam's perspective Dean seemed to have grown up effortlessly, almost overnight, always sure of himself, relaxed and perfectly reliable, everything that made Sam feel safe and everything Sam ever aspired to be.

It wasn't really until he'd reunited with Dean after Stanford that he began to see the cracks in Dean's cool older brother façade.

The discovery made him feel equal parts curious and betrayed.

A similar sentiment echoes inside his chest now when he hears Dean talk about having no grass on the infield.

Dean's been to Heaven, Hell, Purgatory and the realm of the fairies; he's been turned into a vampire and a demon; he's been chosen as Michael's vessel, a Men of Letters legacy and the Righteous Man destined to start and stop the Apocalypse. Each time Sam lost another piece of his big brother, and now that the Mark of Cain is eating away at him, Sam knows that there are days when his brother stares into a mirror and no longer recognizes himself – and there are days when Sam doesn't recognize him either. So it's really not like Dean hasn't already given more than enough.

But, screw that, a yarrow-crazy witch now had to go and take away another large chunk of what makes Dean Dean.

Part of that chunk happens to be the Mark, so Dean seems to figure it's worth it, yet Sam disagrees.

The thing is, he misses Dean being the invincible older brother, the one who held Sam together with a smile, a joke and a gun in his hand, he has for a while. He wants Dean to take his hand and tell him, As long as I'm around, nothing bad's gonna happen to you. He wants Dean to assure him, We'll figure it out, okay, just like we always do, and look like he actually believes that.

Ever since he cured him, Dean's been leaning on him more, and while Sam's never felt particularly comfortable taking care of Dean rather than vice versa – maybe also because Dean finds it hard to let anyone take care of him, go figure – he thought he was doing alright. Except that now he's old and big enough in comparison to be Dean's father, dammit, and that's just a bit too much to take.

He stares at his brother's little face and thinks of how people have constantly pushed roles at Dean, mostly Dad and Sam himself, from an age where Dean had no idea who he was, and yet somehow his brother still managed to emerge from all that as quintessentially Dean.

He thinks of Dean wearing Dad's too big jacket, his too hard lessons, his too heavy expectations. He thinks of Dean wearing strangers' mindless prejudices. He thinks of Dean wearing guilt and anger and grief and trauma. And now apparently puberty too, God help them.

They're struggling enough with everything Dean is. It seems unbearably cruel to burden him on top of that with all the things he's not.

Sam's never been more relieved than when he sees Dean back to his normal self, homicidal Mark and damaged liver included, a hint of stubble on his tired, well-worn face, broad shoulders filling out his black jacket. Sam wishes they could live in a world where Dean doesn't need to run from supernatural claims and fears and hide beneath layers and layers of lies and fake identities, a simpler, better world where Dean can just breathe and be himself. Even if it means that Sam will have to take one for the team and listen to Taylor Swift for the rest of his life.

Before saying goodbye to Tina and getting back into the car, Dean threw his teenage gangsta outfit into the nearest trashcan. The absence of the hoodie and the Underoos and the firm presence of his – undeniably older – brother behind the steering wheel are making Sam lightheaded enough to share his complicated train of thoughts. What actually comes out of his mouth, though, is, "No more clothes."

He blames Taylor Swift, and possibly Obama.

Dean raises an eyebrow at him. "Didn't know you had such a nudist streak, Sammy." But the corners of his eyes crinkle good-naturedly and Sam can see that Dean gets what he's been trying to say all the same.