The moment Timmy agreed, Jamie was already sprinting downstairs, his footfalls thumping the wooden stairs and making the entire house shake. He made it into the living room, took a hard left into the kitchen, and immediately dove behind the counter.
Timmy was already dressed in Charles old clothes. His shirt stretched taut around his huge biceps and pecs and his sweats were practically bursting at the seams. Timmy stood with his hands on his hips and puffed out his chest. His cock had softened and his balls hung heavy between his legs. Timmy was already beginning to realize how good it feels to be jacked and strong. He smiled at his reflection in the oven. He liked the way he looked.
Timmy walked outside and into the street. He felt his new muscles bounce and shift. They felt so good. He walked with an exaggerated swagger, his ass jiggling and his thick thighs fighting the fabric of the sweats. Timmy walked into the convenience store, the bell above the door chiming.
"Hi!" the cashier greeted.
Timmy was surprised. It was a pretty girl, and she seemed excited to see him. He had no idea what it meant to be 'sexy' before this morning. He just smiled, and felt the same heat building in his body that he did before growing.
"Hey," Timmy said, his voice still a little boy's voice. He coughed and said it again, this time his voice a little deeper. "Hey."
The cashier giggled and turned away. She couldn't help but smile, she thought the kid was cute.
"So, um, I need new clothes."
"Oh yeah?" the cashier said, her back to the customer. She was busy trying to keep her blush from getting worse. "Well, there are some shirts over there, and jeans."
Timmy bought the largest sizes they had. The cashier was confused, the sizes were so big! Much bigger than the boy needed, even for his size. She asked Timmy: "Don't you want to try them on?"
"No," Timmy said, smiling. "I don't."
"You can't buy these. They're too big."
Timmy pouted and thought hard. What would his big bro do?
"OK, I'll try them. Can you help me and say would they fit me?"
"Um, okay, sure," the cashier replied.
Timmy went to changing room and the cashier followed. She helped Timmy undress and felt the heat in her face grow. She had never touched a boy before and Timmy was so handsome, and so built! When the young boy stood only in his underware, the cashier was shocked. She reached him and put her hand on his cock and felt how big and hard it was. She looked up at him and he was smiling.
"Do you like it?"
"Oh yes," the cashier breathed.
"Do you want to see it bigger?"
The cashier could not take her eyes off Timmy's cock. She was panting, the heat inside her building.
"Yessssss"
Timmy felt his cock throb. He felt so hot. He had to cum. He felt the pressure in his nuts grow and then release. The pleasure was amazing. His balls grew so big so fast. They filled his underwear and then his underwear tore, the elastic popping and the cloth tearing.
His cock was growing. Inch after inch after inch. Timmy's eyes rolled back. It was the most intense thing he had ever felt. It was even more intense than the orgasm he had just hour ago in the bathroom with his older brother. The cashier was on her knees. Her mouth open. Her eyes staring at the incredible thing happening before her. She was transfixed, her hand rubbing her crotch through her panties.
Timmy tried to put on the clothes he choosen. The jeans fit him nicely, except his package was too large. His cock pushed the zipper apart, his shaft bulging through the tear in the denim. The shirt was even more of a failure. His arms could not fit and his pecs were about to ripp the thin fabric.
"Is it the largest size you have?"
"Yes, yes," the cashier said. She were pleasure herself looking to the stud in front of here. In a moment she left to the bathroom.
Timmy grab the clothes and the same for his brother and left the store, money were on a cashier desk.
When Jamey opened the door, he realised that now he were shorter than his "smaller" brother. Timmy were taller than him for just a few inches. Timmy smiled at the sight.
"Timmy! What the hell?! You are too big now! What are we going do with that??!" .
"Because it feels good. And I wanna be like you. Big and strong and sexy." Timmy put the bag on the ground and grabbed his brother's dick. "I want you, too."
Jamey felt so much pleasure by his brother's hands on his dick.
"What if someone finds out? It is bad, very bad. We should stop."
"But it feels sooo good, and you said we can do whatever we want!"
"I know, but.. but..." Jamey moaned as his brother began to stroke him.
"Come on, let's grow, together!" Timmy said with a naughty grin.