"Actually," Evan said, clearing his throat. "Would you mind if I tested my theory with a little bit of roleplay?"
Mark nodded his consent, as his brother's piercing eyes locked onto him. "And I say roleplay just to let you know this isn't how I truly feel. This is an act. If I'm wrong with it, or you get uncomfortable, let me know and I'll drop it completely, okay?"
"Dude, it's fine. Just... show me what you're thinking."
With his twin's agreement, Evan let himself fall into character. Mark watched as his back straightened, and he pushed his shoulders back into perfect posture that only enhanced his size. He smirked down at his brother. "Come over to the table," he commanded, and it was a command, his voice far too strong for resistance. Obediently, Mark followed him over to his desk, pushing the Chronivac to make way for his gargantuan twin. Evan placed his elbow on the table and offered his hand. "Wanna arm wrestle?"
Mark startled. "W-what?"
"Arm wrestle," Evan repeated, grinning. "Y'know, when I was a young, little girl, you wanted to arm wrestle me all the time. You always won. What do you think, bro? Think I've got a better chance now?" He flexed his biceps as demonstration, watching the fibres tighten and raise a soccer-ball-sized lump.
Mark gulped. "Are you sure?"
"C'mon, you're not scared of losing, are you bro? Fuckin' pussy." The way Evan spoke to him was undeniably rude, yet Mark still felt a shiver run down his spine. Somehow, he was liking his brother like this. Gingerly, he rested his own arm on the table, clasping Evan's hand tightly and trying not to think about how much his brother's paw dwarfed his, and how exhilarating that fact made him feel. Slowly, he began to push.
"Bro, are you even gonna start yet?" Evan teased, then looked down at the grimace that was breaking over his brother's face. "Oh, you are? I couldn't even feel it!"
Mark gritted his teeth and pushed harder and harder. Evan's arm didn't even twitch. His arm wasn't even flexed. Yet, for all the effort Mark put it, it wouldn't budge. Evan scoffed. "C'mon, surely you can to better than that."
Panting, Mark broke off and shook his head. Evan rolled his eyes, and flashed a smug grin. "Okay, pipsqueak. I'll throw you a bone. You can cheat and use as much of your body weight as you want, okay?"
Mark hated that the new nickname elicited the largest response yet, a twitch, a shiver in his shoulders that he was sure Evan hadn't missed. Still, he accepted the challenge. Standing up, while his brother remained sitting, he began to lean all his body weight into Evan's arm. Evan just looked bored. More and more pressure he put on the titanic muscle, straining for it to give even an inch towards the table. "Is that all you've got?" Evan goaded, but Mark swore he could see the slightest twitch of muscles tightening, the tiniest bump forming, the only indication of strain on his otherwise superhuman twin. It gave him a touch of hope that maybe, just maybe, he could overcome the odds and win.
"Well, this has been fun," Evan yawned, and with one hard flex managed to shift Mark's entire weight, making him stumble back. Seconds later, his hand slammed into the desk with enough force that he winced, sure his wrist would be bruised tomorrow.
"Oops," Evan said, though he didn't sound very apologetic. "But honestly, it's not my fault. I can't help that I've got a weakling for a brother. I mean, I've seen twigs put up more resistance!"
Mark's face rushed with heat as his brother continued to boast and humiliate him. Then, suddenly, his feet were off the ground as he was lifted by the scruff of his neck and tossed around like a rag doll. Evan grinned down at him. "Look, bro, you weigh basically nothing to me. It's ridiculous how small you are compared to me."
Just as Mark was getting used to the feeling of weightlessness, the pace abruptly changed again, as Evan slammed him down onto the bed. "Speaking of small," he sneered, as his fingers scrabbled at Mark's pants, unbuttoning them once more. He pulled out Mark's cock, which was straining stiff as it flopped free from its confines.
"Look at you... How long are you?"
Mark knew the answer, but, looking at his brother's cock hanging flaccid and free and so absolutely massive, he felt a sudden urge to lie. "Nine inches," he mumbled.
Evan laughed. "What was that, bro?"
"I said, nine inches."
"Sure." Evan winked at him. "That's what you tell all the girls. But I, for one, think we need a measurement. Just to make sure you're not lying."
He reached into a drawer in Mark's desk and produced a measuring tape. The cold metal made Mark gasp as it pressed against his sensitive skin. "Well, would you look at that! You're only seven inches," Evan crooned. "Now, why would my brother feel the need to lie about something like that? Could he be feeling... self-conscious? Or maybe, he's just embarrassed with how utterly inferior he is. Especially when faced with a monster like mine."
Evan hefted his own cock, two and a half feet long and still flaccid. He showed off his melon-sized balls, the girth and sheer insanity of its length for Mark to see. And when he was done with that, he let his shaft flop over Mark's with a sound of meat against meat. Mark gasped as just the weight of Evan's elephantine cock sent shockwaves up his member.
Evan sneered as his cock dwarfed his brothers. "Look at how small you are. You're fucking tiny! Not even a quarter if the size my cock is, and it's soft. Honestly, bro, how can you even pleasure someone with a tiny prick like that?" He reached down and clamped one of his hands around Mark's shaft. "What girl is gonna want you? You'd barely be able to touch the sides of her womb with a little dicklet like that. They'd want a true bitch-breaker like mine."
He scoffed as Mark shuddered with each word, his cock jolting in his massive hand. "Honestly, I'm embarrassed I have to call you my brother. You barely deserve to be counted as a man, pimple-dick, let alone classed with people like me. I'm extraordinary. I'm fucking superior. And you?" He punctuated his next words with a thrust of his hips, mashing his heavy cock against Mark, "You are a pathetic, weak little nobody!"
With a gasp, Mark came into his brother's hands, snapping both of them out of their daze. Mark whimpered as his body trembled and shook, seed pouring out of his respectable seven-incher and running down his twin's arm. Evan stared in shock, impressed, yet surprised that he'd made his brother cum simply with his words. The act dropped, and he cradled the smaller man against his chest.
"Are you alright?" he whispered, voice back to that demure, gentle tone.
Mark whimpered again, but nodded. "Y-yeah. That was intense."
"No kidding," Evan replied, chuckling. "It felt so weird to act like that. I was going against everything in my nature. But, hey, I guess my hypothesis was correct."
He leant down, his lips brushing Mark's ear as his voice dropped back to a deep, demanding, sultry growl. "You like being humiliated. You like being reminded how inferior you are, and how much better I am, don't you?"
The voice sent shivers down Mark's spine. Wordlessly, he nodded.
"Well, while it's hard to keep it up as I am now, but, if you'd like, I can use the Chronivac and make my personality suit you better. I'll make myself your perfect fantasy," he offered, and it was such a deliciously tantalising thing, like the snake offering Eve the apple. "All I want to do is make you happy, bro. And if this is what would make you happy, I'll do anything to make it come true. Just say the words."