"...give me really big pecs, Ty? I've always admired guys with huge chests!"
Ty smiled down to Dustin.
"Sure big bro, its no problem, just tell me when to stop!"
Ty closed his eyes, concentrating on his older, yet smaller, brothers chest.
Dustin first felt a weird sensation welling up in his chest. Then it just felt warm. As he looked down, he could see his shirt slowly filling out. He felt his under-developed pecs swell out, forming a nice line down the middle. His t-shirt kept getting tigther, showing off the new definition he was getting. He grinned, feeling his two swelling orbs of muscle, as he looked up at his massive brother.
"This feels great Ty! They must be 45" by now!"
Ty grinned. "I've only just begun!"
Dustin grunted, as he felt them growing faster in his hands. His shirt was almost at the breaking point as they swelled up and out. They had to be at least 55" by this point, and they were starting to look like breasts. Thast when he felt his shoulders start to widen, allowing for his pecs to look like giant orbs of manmeat. His legs shivered, finding it hard to hold up his massive top, as he felt the growth subside. He turned in the mirror, to find that he had a 70" chest on top of a 28" waist.
"FUck Ty! These are awesome!"
Ty's hard cock dripped pre all over the floor as he looked at his big chested brother. His mind raced with thoughts of what he would do next.