He's already taller AND stronger than Nate, he needs to see his reaction now!
Looking down at his tattered clothes, Chris thought to himself, it'd be more intimidating for Nate if he saw his "little" brother stretching out HIS clothes. That'll really sell how big he's gotten.
So Chris sneaks into Nate's room, making sure he wasn't there, and changes out of his clothes made for a kid 2 feet shorter and a lot less muscular. Digging through Nate's clothes, he grabs one of his bigger football jerseys, a pair of shorts, and his underwear.
As he gets out of his old clothes- tearing off the poor underwear- he frowns a bit, seeing he's only 5 inches flaccid. Yeah, probably huge for a 12 year old, but he knew Nate's was still bigger. Pulling on the clothes, Chris smiles proudly, feeling how they fit him. The shorts ride up several inches above his knees, tightly sticking to his thighs. Even through both layers of clothes, a bit of bulge can be seen in his crotch. His ass also completely fills out the shorts. Since he's taller than Nate, the jersey leaves an inch of midriff exposed. He also feels how the fabric stretches over his shoulders- He's definitely wider than Nate is too.
However, his appreciation of his growth is cut short by the sound of footsteps approaching the door.
"Hey, Shrimp, what do you think you're doing in my room?"
Nate slams open the door, and stops. His mouth is wide open, like he was ready to shout more, but he now just looks in shock, seeing his newly huge "little" brother standing there, looking DOWN at him.
"Oh, sorry. Those little baby clothes didn't fit anymore. Yours are a bit tight... But they might work for now." He flexes a bicep, and there's an audible tear sound as the bottom of the jersey's sleeve tears open. "Whoops. Maybe your clothes are too small too."
"Wh- You- How did you-"
"How did I get so big? Who knows... Maybe my wish came true."
Hearing his younger brother's sarcastic comment snaps Nate back to reality, and he gets angry, seeing his torn jersey.
"That's one of my favorite jerseys, twerp!"
He tries to grab at the ripped sleeve, but Chris' hand stops him. His veins bulge out as he locks his older brother's wrist in an iron grip.
"It's not nice to touch people, Nate. Especially those bigger than you."
The words stung Nate, truly taking in how Chris has changed, craning his neck up to look into his brother's eyes, two whole inches taller than him.
"Oh, sorry, it's a bit hard to see you over my pecs, isn't it?"
Before Nate can protest, Chris reaches both of his huge hands under Nate's armpits, lifting him up off the ground to eye level. He notes its not as easy as he'd thought- He's definitely bigger, but not SUPER bigger. Not yet, at least.
Nate squirms in his arms, not used to being picked up so easily before, and definitely NOT by his little brother!
"Now, there's gonna be a lot of changes around here, Little bro. Mainly, you're going to do whatever I say from now on!"
Nate glared back at Chris, his eyes filled with anger, but also, a lot of fear. However, as he looks into his eyes, he realizes something, and smiles.
"Yeah? Your face hasn't changed at all- you're still just a boy. Sure, you're taller and stronger now, but you're not a man."
Chris realized he was right. He only made himself taller and stronger- his face still looks like a 12 year old's, and his body is still pre-pubescent. Dropping Nate to the ground, the older boy wincing as he falls on his ass, Chris gets the idea for his next wish.
But what did "manlier" even mean by Nate's standards? Should he wish for a deeper voice, hair everywhere, a beard? Or maybe just having a bigger package will make a guy like Nate squirm...
"Alright. You want me to be a man? I'll be manlier than you! I wish..."