The room was dim, lit only by the flickering blue haze of the TV that Dean forgot to turn off. A box fan rattled in the window, humming like it was trying to soothe the whole world to sleep.

Dean sat on the edge of the bed, bent forward with his elbows on his knees. His shirt was off, old jeans clinging to his legs, and his eyes—those sharp, tired green eyes—were focused on the small bundle of toddler chaos curled in his lap.

You.

You were maybe two and a half, if that. A mop of sleep-mussed hair stuck up at funny angles, a thumb stuck stubbornly in your mouth as you nestled against Dean’s bare chest like he was the whole damn universe.

Dean’s hand moved slowly down your back, warm and careful, feeling every shaky breath you took after crying yourself awake twenty minutes ago.

“Shh,” he murmured, voice scratchy and low. “You’re okay now, kiddo. Gotcha.”

You sniffled. A hiccup. Then your little fingers, sticky with juice from a forgotten bottle, clutched at the dog tag hanging around his neck. The metal clicked softly against your teeth as you bit it. Teething. Again.

Dean sighed.

“Gross, dude. That’s not a chew toy.”

But he didn’t take it away. He just adjusted you so your cheek rested over his heart.

He hadn’t signed up for this.

He was barely 18. His senior year had already gone up in flames when Dad disappeared on a hunt in Arizona last month. Sam was still asleep, snoring on the far bed, his long limbs tangled in a blanket that had half-fallen to the floor. And then there was you—this tiny surprise no one had asked for, especially not Dean.

A half-sibling. An accident.

Your mom had shown up to the bunker two years ago with a blanket-wrapped bundle and a face tight with resentment.

“I’m not keeping it. He doesn’t want it, and I sure as hell don’t either.”

She hadn’t even said your name. Called you an ‘it’ .. would’ve been funny if she wasn’t serious.

Dean had stepped forward. He always did.

Now he wiped your nose with the sleeve of his Henley and pressed a kiss to the top of your head, even though you smelled like apple juice and baby shampoo and maybe pee.

“You know what?” he muttered, rocking you back and forth. “Screw them. You’ve got me.”

You mumbled something incoherent, maybe his name, maybe a dream. Your little body went heavier in his arms, falling limp the way toddlers do when they finally give up and go back to sleep. Your fingers, still curled around his dog tag, relaxed.

Dean stared at the ceiling, jaw clenched, a war behind his eyes.

He wanted out. He wanted a normal life. He wanted Mom back, and Dad to quit being a ghost with a gun, and Sam to stay a kid a little longer.

But for now?

He tightened his arms around you and whispered, almost too soft to hear:

“I’ll be your dad if I have to. Your brother. Hell, both. Just… don’t let me screw this up.”

Outside, a truck rumbled past. The fan rattled.

You snored.

And Dean Winchester, barely grown himself, sat up all night with a baby sibling who had no one else.