Aaron tried to avoid Kyle for the rest of the weekend, stung by the humiliation of being forced to suck off his horny brother's big dick. It wasn't terribly hard--Kyle seemed to spend every waking hour eating, lifting, or jerking off. Aaron only saw his brother at meal times, and only when the whole family was there. Shockingly, neither of their parents seemed that concerned with Kyle's sudden changes. Their mother simply remarked about Kyle's big appetite, before serving him fourth or fifth helpings. Their father was worse, commenting approvingly that Kyle had finally gotten into working out, and offering to buy extra weights for the basement. Aaron wanted to sink into his chair as the two men discussed how many new weight plates to buy, and how heavy they should be. Kyle wanted as much iron as he could get, and Dad readily agreed to buy dozens of plates--as long as Kyle promised to use them, which he readily did. It must be Madame Illusia's magic, Aaron thought to himself, it was the only explanation for how blasé his parents were about the whole thing.
The following week, Aaron rarely saw Kyle. He knew that his younger brother had gym class at school, but despite that it seemed like every afternoon after classes Kyle was in the basement, working out, putting the extra plates their father bought to good use. Aaron began getting up early, leaving home before Kyle was even awake, willing to spend an hour on campus before school even started if that was what it took to avoid his growing sibling. Aaron began to stay late after school as well, spending time in the library or a lab, diligently studious. His grades were the only bright spot in his life: they were skyrocketing due to his newfound academic focus. When he did get home Kyle was usually in the basement, and Aaron was glad he didn't have to see what was going on.
But Aaron couldn't ignore the signs that his brother was still changing. Large tubs of protein powder took up residence in the kitchen. Every day became laundry day, due to the sweaty clothing that Kyle offloaded into the hamper. Every few days, more weight plates arrived. And of course, every night Aaron could hear it: Kyle in the next room, grunting in his deeper and deeper voice as he jacked off. Even the sound of Kyle's bed shaking was louder. By Wednesday, Aaron had bought earplugs so he could get to sleep.
Friday night brought the worst news possible. As Aaron got home in the evening, he found a note out on the dining room table: "Left town to visit Aunt Bea," it read, "Be back Sunday night. Love, Mom and Dad." His mother's aunt had been in poor health for some time, and his parents often visited her. Since she lived several hours away, they usually stayed the weekend. That meant he was home alone. With Kyle. For the weekend.
Freaking out, Aaron crept around the house carefully. But Kyle was nowhere to be found. Aaron searched high and low, but Kyle simply wasn't there. The older brother even cautiously went down to the basement. He marveled at the number of weight plates that were scattered about--it looked like Dad had spent a small fortune on Kyle's new obsession! Still, Kyle wasn't there, and as far as Aaron was concerned, that was a good thing.
Finally relaxing a bit, Aaron returned to the kitchen and made himself a light dinner. He didn't have much of an appetite any more, and a salad with a glass of milk on the side filled him right up. He retreated to his bedroom, put on his headphones, and began to read. At around ten he put his book and headphones away, slipped in his earplugs, and went to sleep.
Aaron awoke suddenly. The room was dark, but he could sense something--someone--next to his bed. He turned on the light on his nightstand, and nearly screamed at what he saw.
A towering brute of a man looked down at him, scowling. He could barely recognize Kyle's face under the dense beard, and the huge, musclebound body was nothing like his brother's athletic physique. The man was enormous, easily six foot four, and undoubtedly north of three hundred pounds. His tight clothes left little to the imagination: his short sleeves were tight around his huge biceps and triceps, and the top three buttons of the shirt were undone, showing off the deep cleft between his thick pecs. His shoulders were impossibly broad and beefy, yet his waist was tight and narrow despite the fact that thick abs were visible under the shirt. His legs filled a pair of "loose" jeans to the point of bursting, the tough fabric wrapped around his mighty quads like superhero spandex; between those thighs was the biggest bulge Aaron had ever seen. "Hey bro," Kyle rumbled, his voice deep and rich.
"Wha- what do you want?" Aaron stammered, his voice squeaking with fear.
Kyle's scowl became a smirk. "Just got back from a college party," he said proudly. Aaron noticed a faint scent of beer, mixed with Kyle's overwhelming natural scent: something manly and musky. He would never admit it to anyone, by Kyle didn't just look amazing, he smelled that way too.
"H-have you been drinking?" Aaron demanded, his voice almost shrill.
"You bet," Kyle replied with a chuckle, which was followed by a low burp. "I've been doing more than that, though..." He reached down to grope his crotch, squeezing it ostentatiously. Aaron simply stared, dumbfounded, unwilling to ask what else Kyle had been up to. His younger brother told him anyway. "Two college girls, two college guys," the young hulk boasted, "I decided to really try everything out, you know? The girls were fine, I guess. But fucking those college boys was amazing! Their asses were so tight! You should have heard them moan when I fucked them!" A shudder ran through Kyle's huge muscles as he remembered his earlier conquests. Aaron watched in horror as Kyle's big bulge began to shift, the shaft starting to swell, pushing down one tight pant leg. Aaron gulped audibly as it got bigger and bigger, swelling past the eleven inches he'd been forced to service a week earlier.
"Um, maybe you just need to find the right girl..." Aaron offered, weakly.
"I'm not even looking for the right guy right now!" Kyle laughed, "I'm just horny all the time! As much as I like jerking off, fucking a dude is what really does it for me." Kyle began unbuttoning his shirt, revealing his cobblestone abs, two at a time. He shucked off his shirt, giving Aaron a great view of his huge chest in all its glory, the muscle so thick that the nipples pointed downward. "Admit it, I'm pretty hot," Kyle purred, putting his fists on his hips, flaring his lats out, tensing his mighty chest. Aaron's voice caught in his throat. He couldn't get words out, only pathetic choking sounds. Kyle laughed again, then unbuttoned and unzipped his jeans. "Bet you'd like to see everything..." he growled, as he slowly pulled his jeans down over his mighty quads.
"N-no, I don't need to see it!" Aaron stammered. But he stared at the bunched up fabric of Kyle's underwear, half of his brother's cock jutting out of it on one side.
"The college boys said that too, at first," Kyle rumbled, kicking his jeans aside, "But by the time I was done with them, they were begging for more!"
Aaron watched as his younger brother stood up straight, bringing his legs together, flexing his huge thighs so every bit of his bloated quadriceps was on display under the thin skin. His big dick stretched out further, getting longer and harder, escaping more and more of his underwear. "Thirteen and a half inches," Kyle growled boastfully, "one of the boys measured."
Aaron sprang up, throwing the covers at Kyle to create a distraction so he could flee. He was out of his bed and half way to the door when a huge arm grabbed him and roughly flung him back onto the bed. "You're not getting away from me that easily!" Kyle snarled. He reached down and grabbed his underwear, casually tearing it off of his body, the fabric no match for his strength. "This morning I was 320 pounds of pure muscle. By now I'm even bigger!" Kyle was nearly shouting, his deep voice filling the room. He raised his huge arms and flexed hard, his biceps mounding up like footballs under his skin, his enormous erection jutting out menacingly. Aaron shrank back against the bed, staring up in slack-jawed fear. Then his brother was on him, holding him down with one hand while brutally tearing his clothes off with the other.
"Now what do we have here?" Kyle purred, his anger of a moment earlier turned to amusement. "You hard, bro?" Kyle snickered, one of his thick fingers pressing against the head of Aaron's cock. Aaron's small, undersized dick was fully erect, the first time it had been so since the fateful night when the world had been turned upside down. Mortified, Aaron went pale, staring down at his hard little dick as his hulking brother teased it. "Bet you want me to fuck you, just like those college boys..." Kyle growled, as he gave Aaron's small erection a firm squeeze. The older brother's head swam and he became dizzy, a rushing sound filling his ears, drowning out his younger brother's cruel laughter. Kyle was still talking, mocking Aaron's dick it sounded like, or perhaps the dicks of the college boys--it was hard for Aaron to follow, the blood was pumping so furiously in his ears. His body went limp and his vision narrowed, the edges of it brightening to match the white noise that was filling his ears.
Aaron offered no resistance as Kyle picked him up and pulled him in closer. He made no sound, other than a low groan as he felt Kyle's huge cockhead spread his cheeks and nuzzle his hole. He gulped air as he felt the huge tool enter him, unable to react any more to the pain of having such a big dick force its way into his virgin hole. "You like that, bro?" Kyle grunted, driving his dick in deeper, not bothering to give Aaron time to adjust to its size. Aaron wanted to protest, to demand an end to the violation of his ass. But he could only let out a gurgling sound that produced chuckles from his enormous sibling. "Bet you love having such a huge cock in you," Kyle sneered, arrogance filling his voice as he pulled back, withdrawing most of his tool from Aaron, leaving only the head inside. "Yeah, you totally love this," Kyle purred, running his fingers up and down Aaron's still-hard little dick. Aaron whimpered softly, and it was clear to both of them that it was a sound of pleasure. "Knew it!" Kyle laughed, launching himself forward, ramming his dick all the way into his older brother. That produced a loud moan from Aaron, who slowly found himself returning from the brink of unconsciousness. As Kyle began to fuck him in earnest, he could feel his body reacting, betraying him to the massive brute. Aaron cursed the treachery of his own voice as he was unable to stop the groans of pleasure that escaped his throat; his only consolation was that for the most part they were drowned out by the increasingly loud and bestial grunts coming from Kyle. Yet as Kyle became louder his thrusts became harder, sending greater pleasure coursing through Aaron's body. Having been stretched to accommodate Kyle's massive tool, Aaron's own moans became shrieks of lust as he was pounded furiously.
Aaron cracked. "Yes!" he panted, reaching up to admiringly caress Kyle's huge muscles, "More!"
Kyle's booming laugh filled the room, turning into roars as he redoubled his efforts, slamming his dick into Aaron as hard as it would go. His domination of his brother fully established, he ruthlessly ravaged Aaron's hole, exulting in his victory. The college boys had been fun, but conquering his older brother filled him with immense satisfaction and pride. His brother's moans and gasps were music to his ears, and they only encouraged Kyle to continue on his new path: he would lift more, eat more, grow more, and of course fuck Aaron more. The prospect of it sent him over the edge: the huge man's roar shook the room as he came, his dick unleashing a massive load of cum, shooting it deep into Aaron, causing the smaller, older brother's on little cock to erupt as well, the little load splattering onto Kyle's powerful abs.