John had never felt a particular attachment to his body. It was a tool, his first and best weapon against the darkness that dogged their family.
It should have been easy, entering his son's body. Sam's body was taller than his, thin and wiry and fast. They shared blood. It should have been like handling a new weapon: strange but familiar.
It wasn't. Sam's body felt caged in, too big for his own skin. John couldn't help but think it was the taint of Yellow Eyes' blood—infecting his boy, making his body reject his father on every possible level.
John knew Dean's body would have been welcoming, like slipping on a well-loved pair of gloves. Dean was his boy.
His too-pretty, slut of a boy. It should have come as a shock, but it didn't, when he opened his eyes after a wave of vertigo to the sight of Dean's head being pounded into the headboard as he thrust an aching, too large cock into his eldest's ass.
"Sam, fuck, don't stop," Dean panted, twisting around to stare at John with bright eyes, green as Mary's used to be when she was just about to come.
John's stomach roiled. Whether it was curling tight with arousal, or clamping down on nausea, he couldn't tell, but his hips drew back and pushed back in, slow, as though of their own volition. As though Sam's body couldn't help but fuck his brother.
"You close, baby?" comes out of John's mouth, unbidden. He realises his hand is wrapped around his boy's cock, wet with the slick Dean's cock has obviously pumped out while Sam had been fucking him. "Your pussy's so fuckin' wet, boy."
"'m not a girl, Sammy, fuck you." John can feel a slow grin spread out over his face, the first familiar thing this body's let him feel. He's settling into it, the fog he'd first felt weighing down his limbs evaporating out through his pores, leaving his skin tingling, bright with heat wherever his skin pressed into Dean's.
"You're whatever I say you are, boy," John said, knowing the truth down to his bones, down to Sam's bones. "Your sweet little cunt's desperate for my come, practically starving. Don't you think?" He twisted his hips sharply and smirked when Dean couldn't help but let out a sharp, broken cry.
On the bedside table, Dean's phone started to vibrate. John slanted a look at the screen, and let his breath hitch when he saw the bright letters spelling out DAD.
He was in Sam's body—only stood to reason that Sam got swapped into his and was desperate to get hold of Dean. Sam probably wanted to make sure Dean wasn't dealing with their father having a freak out about find them In flagrante. Probably thought Dean was getting his ass whupped even as his hole dribbled out lube and maybe come.
"That's Dad calling, Dean," he grit out, feeling inspired. He jerked his son's cock softly, just a tease. "Probably wants to talk about a hunt. Think I should pick up, tell him his son's too busy spreading his legs to come to the phone?"
"That's sick, Sammy," Dean laughed, breathless. He arched his back off the bed, fucking up into John's fist and down onto his cock, eyelids heavy.
"Mmm, but you like it, don't you? Like the thought of Dad knowing. What do you think he'd do?" He jerked forward hard, fucking his (son's) cock, so big, into Dean's prostate, easy as torching a corpse. "Think he'd freak out? Or do you think he'd want a piece of you for himself?"
"Dad wouldn't do that, Sammy, you sick fuck," Dean laughed and reached up to tangle his fingers in John's (Sam's) too-long hair, pulling himself up for a kiss.
His boy's lips were soft, big like he'd been kissing all day, and he kissed like John was his everything. Kissed like Mary kissed John on their wedding day.
John kept fucking Dean, trading filth and laughter with his son, and came to the sound of Dean's phone vibrating off the table.