Just then there was a knock on the door.
John walked in and looked at his gym teacher standing there angerly in a Batman costume as this mountain of a man stood there flexing.
"I'm so sorry about this Mr. C"
"Don't applogize, just fix things already."
"Now wait a minute, why do I have to give this muscles back. It was your mistake and I like being the biggest guy in the room." Tommy said.
"I get it, but I need to make things right."
"Now wait just a minute," Tommy said as he began to charge towards John.
It was too late. Suddenly, Tommy felt as though his whole body was shrinking. His mighty biceps felt as though they were deflating as did his shoulders, pecs, abs, thighs, and yes, even his crotch. It felt like the world around him was growing while the reality was he was shrinking back into his thin frame the muscles and the strength they gave him draining quickly.
In mere moments, he went from being a 6'5 foot Adonis back to a weak little boy.
He frowned looking at his figure and cringed the moment he spoke again as his girlish voice returned, "No!" He shouted he began crying like the little boy he once again was.
As Tommy shrunk back down to his 12 year old self, Brian was finally about to return to himself and could hardly contain his excitement.
Brian felt a tingling sensation in his calves. He planted his feet firmly, and his calves began to grow. Slowly but surely, inch by inch. He moaned as his thick, defined muscle piled itself onto his lower legs. The muscle now protruded out the back of his legs massively.
The growth next moved up his legs to his quadriceps. The already defined muscle began to expand, layers and layers of hard muscle piling back on.
He tilted his head back and moaned loudly as the muscle on his firm butt began to balloon out. It kept going and going until his oversizes shorts once again fit snuggly upon him.
He felt a tingle in his upper stomach, and moaned as a line appeared down his stomach. At the top, just below his chest, two cinder blocks emerged from his stomach. Another row emerged below it, and another, and another. He stared in awe at his 8 pack abs returned.
His small pecs began to expand, bigger and bigger. He laughed as his back widened. His traps expanding, and his neck thickening greatly.
His hands started to grow, becoming heavier. The growth moved up his forearms as they swelled. He gasped as his biceps and triceps expanded as well, nearing 20". He flexed them both, missing the feeling of strength they provided.
Finally, his once again massive body decided to go through puberty all at once. Hair sprung up on his chest, and a treasure trail down his abdomen. His face finally returned to that of a charming, steely man with his stubble once again growing in on his cut jawline.
Finally the transformation stopped.