A lazy stream of the big man's cum oozes out of Adam's ass as the huge teenager slumps to the ground, exhausted from being plowed by the absolute monster his father had become. A hazy grin forms across his lips having never been so satisfied in his life. He feels himself drifting to sleep as he hears the audible squelch of his dad beating himself off just moments after breeding his son. But, as the pool of pre-cum growing around Adam's dad's feet reaches his face, Adam's jolted to alertness as he sees a familiar face popping in from the front door. His brother.
Xavier had class today at the local college. Adam's twin brother, the boy was every bit as scrawny as the now-muscular teen used to be. Xavier's eyes widened, the teen almost dropping his phone as he looked at a huge, hunk of a man getting onto his hands and knees. The guy looked to be his age, like a better version of himself; thickly muscled like a college wrestler, a handsome face framed with thick facial hair and a cock that could satisfy an entire sorority... or frat. It was that scared, aghast look that the guy on his knees returned to him that made Xavier realize that he was looking at his twin brother, Adam!
"H-holy shit, Adam?" Xavier yelped, taking a step back. He hears a dark chuckle and his eyes moved from his hunk of a brother... to a gargantuan muscle monster that sat himself on the family's couch in the living room. The huge man practically took up the entire thing by himself. Xavier shuddered as he looked at how brutally thick the man looked, how hairy, yet veiny every inch of him was. The giant tweaked at his huge, thick nipple as he gave the tiny guy a predatory, wolfish grin. Xavier gulped and gripped at the wall as he backed away. He knew his brother was gay, that was the only difference between him and Adam; his brother was a fan of the man, he loved the ladies. But he never expected Adam to get with a monster like this!
"C'mere, son," the huge, 900 pound behemoth growled. "Don't you want to see what your old man has become?"
"Shit, dad?!" Xavier cried.
The lusty father brought his arms up, making his huge biceps pop, a low animal-like grunt blasting from his throat. He looked at his two eldest sons. It was amazing what the special 'sports drink' had done to him and Adam. As Adam stood up, the difference between the two twins was night and day. Before, Adam would've almost been a mirror image of the scrawny wimp that stood beside him. He boned up just looking at the difference.
Adam was turned on as well, the huge college freshman idly rubbing at himself as he took in how puny Xavier looked next to him. Despite being 'straight,' he could see that Xavier was tenting his shorts with his teeny tiny erection. The bigger brother grinned as he loomed over his former equal, his dick jolting as he flexed his big arm, 19" of honed, steely flesh, in front of his brother's face. The smaller brother groaned, his tiny, light fingers finding purchase on the bigger one's arm.
"Show us what you got, Xavier," the huge father cooed, the titan of a man rubbing his crotch as he enjoyed the show. Xavier whimpered as he copied the flex and grimaced as his dad let out a pleased huffed, his hand quickening on giant length. The comparison was just too much for the salacious father; it was like comparing a toothpick to a real man's arm!
Adam was all smiles as he lifted up his brother's shirt, revealing emaciated pecs and a sunken in midsection. The huge brother crunched his abs and threw his arms behind his head, his big pecs casting a shadow over his ribs while his tiny brother's did not.'
Xavier tried to swat his brother's hand away, but he was helpless to resist Adam's newfound strength as the bigger brother tore off his shorts. Adam chuckled as he looked at the cummy mess his brother had made in his undies, the crotch stretched out from his groin was little more than a bump compared to the juicy, thick sausage that pressed into Adam's corded abs. He pulled Xavier's underwear to his knees and laid his own length on top, completely eclipsing the tiny pecker underneath.
The boys' dad stroked himself with earnest as he watched the bigger brother lean over and take his former twin's lips into his own. It was almost comical, one brother completely overwhelming the other. The father grunted as Adam spun the smaller man around, his huge dick bobbing with need.
"Shouldn't leave me out, boys," the dad snickered. He got up and made his way to the kitchen to get the flask. With devious grin, the giant poured a little bit of the restored fluid onto the tip of his cock, the potion mixing with the thick film of cum that clung to his cockhead.
Xavier cried out in a mix of lust and pain, his virgin asshole stretched around his brother's enhanced tool. He didn't have time to acclimate to having such a big penis in him before an even bigger cock covered in jizz and some sort of sweet smelling liquid was shoved into his face. The small college boy whined, looking up at his massive, lust-filled father as he was forced to take the apple-sized cockhead into his mouth. The taste was salty, musky, yet sweet from whatever the heck his dad had smeared onto his cockhead.
As he's bred from both ends, Xavier watches...