Dustin found his excitement growing, as he made Ty bigger and bigger. His younger, and previously smaller brother growing larger by the second. Soon, Ty was every bit as big as Dustin.
Dustin paused, looking Ty up and down.
"This is unbelievable!" Ty enthused, flexing in the mirror, watching his thirty inch biceps rise, amazed at the sight of it. Dustin was impressed as well, his twelve-inch manhood rampant and starting to leak pre, he was getting so turned on. He flexed his equally large and powerful biceps, comparing them to Ty's, grinning. "Looking good, Ty!"
Ty blushed and then grinned, and brought one big flexed bicep to his face, and slowly kissed it. Dustin shivered with pleasure at the sight. "Oh fuck Ty..." he groaned.
Ty glanced at Dustin, surprised to see how turned on his elder brother was. Then he grinned wickedly, and began to lick his huge bicep seductively, his tongue running over the thick, hard bulge, tracing the veins, leaving spots of shiny slick skin behind.
Dustin moaned with excitement, pre fountaining down his cock, Ty's not so subtle show working him over. He stretched out with his new power, and Ty began to swell once more, getting taller, six-foot-one, six-foot-two... Getting bigger... 400 pounds, 450 pounds... His tongue working quicker, more eagerly, running over the ever larger bicep that swelled beneath it... 32 inches, 34 inches, 36 inches... His cock hard against his rocky abs, pulsating softly, thick with power... thirteen inches long, fourteen, fifteen...
Dustin slammed more growth into Ty, watching the younger lad swell up larger and larger, muscles bloating furiously, becoming thick and round and packed with power, unbelievably hard, covered in veins. At last, Dustin couldn't take it any more. His cock exploded on its own accord, sending cum through the air, much of it landing on his thick chest and strong abs. As he came, Ty swelled once more, power rushing into him.
Dustin panted raggedly, trying to catch his breath, his mind still buzzing from orgasm. He looked up, to see Ty flexing, seven feet and 700 pounds of rock-solid muscle, mind-blowing 45 inch arms, an eighteen inch dick that defied imagination. "Oh... oh fuck..." Dustin groaned in disbelief, staring at the huge god he had created.