As Jack started to head toward his room, he was interrupted by the noise that emitted from his stomach - a heavy, rumbling sound that gave him pause for a moment. He then smirked and looked down at his stomach. He patted it, and said, "Oh, of course! I worked out and built up a sweat, so of course I'm gonna be hungry!" Just thinking of the chicken and steak in the fridge - brought over to be meals for the boys - made Jack drool with anticipation. For some reason he was feeling well and truly eager to sink his teeth into it.
He barely paid his bookworm brother any mind, and headed into the kitchen. Taking out the kitchen and steak, Jack did not even feel the need to cut it up or try and partition it; he just tore into it with his nails and ripped free pieces of the precooked meat. Smelling the meat made Jack swoon, and the youth quickly took a seat with his abnormally large sized portions of chicken and steak.
The next few moments were spent thinking about getting some salad, but ultimately Jack decided to just keep with his meat. He usually ate a generous serving of salad to make sure he was healthy and growing strong, but today for whatever reason he felt a stronger tug toward the meat, though he still felt inclined to eat his greens afterwards. His mind was tugging him back toward it, and he saw no reason to deny himself what he wanted.
"Hah, I bet by the end of this, I'll be even bigger than ever, and poor LITTLE brother is gonna look even littler." He thought about that, and Jack found himself feeling quite enthused by the idea. He was already the more athletic brother, the one who took more to the blessings of puberty. Everything good he learned in Development Class that would happen to his body, he was starting to see in himself. And he very much enjoyed lording that over his sanctimonious brother.
Jack sat down and dug in, abandoning any vestige of human eating habit as he closed his teeth around the meat, chomping through skin and meat both, and swallowing - then proceeding on to the next bite. He found himself even still feeling voraciously hungry. His muscles were yet to be fully sustained. His stomach demanded more.
"Geez..." Jack commented as he got up to go get himself some more food, "I'm eating like a freaking bear in here..." He did not know how accurate indeed that comment would turn out to be. He was not even thinking there could be anything remotely animalistic about these changes. He just saw them as giving him everything he ever wanted to develop in himself. He was gonna be a big, hairy masculine man who got all the girls his dorky older brother would never be interesting enough to get.
Sure big bro would call that mentality shallow and childish, but Jack called it "victory". After all, there was hardly anything better than enjoying the bounty that life gave to a well developed young man involved in sports.
The young jock, unaware of his changes, uncritically indulged in what the great power from the cabin encouraged in him. And indeed, even as he ate, he was unaware as to the continuing changes assaulting (?) his body; his arms strengthened and grew longer, the nails growing just slightly sharper. He would grow slightly taller, just enough to perhaps be mistaken for the rigors of puberty. What would be less easy to excuse would be the early patchy beard growth coming in on young Jack's face. This marked a trend, the rest of him likewise growing slightly thicker body hair as the transformation continued.
His rear felt a distinct tug as something started to grow at the tail bone, nothing distinctive yet but hinting at the true destination of Jack's changes, rather than the mere "growing man" anticipated by the youth. Jack was due to become a beast, and he was oh so blissfully unawares as to that course as he continued his feast. And what a feast it was.
Jack got up once to go grab some greens to supplement his meal, and before long tore through those as well, concentrated wholly on his perception of himself as a growing young man who needed his nutrients. Jack didn't notice that he'd gone from chuckling to growling lightly as he indulged his appetite, though once he was done he was unaware to this.
Looking at his plate and feeling his slightly swollen stomach, Jack groaned and chuckled, "Damn...that was amazing. I feel so freaking good..." He did note his voice sounded slightly deeper, and he was excited by this, taking it to be more evidence he was in the midst of a growth spurt. He just hoped he kept on growing bigger and bigger.
Getting up and flexing his arms, Jack looked around and wondered - what next then, for the young athlete growing into his mature form? He could go and workout again, possibly needing another shower, or he could just go explore some in the outdoors, a prospect which was feeling oddly endearing to him. Indeed, something was tugging him toward the deeper outdoors, toward the wilder areas away from the human traversed pathways.
Or...he could stay here and try to familiarize himself with his newly grown form. Jack found himself growing rather curious, and wondered what sort of reflection he would see when he went back up to his room and then examined his physique. He saw himself as being a powerfully built young stud, but an itch at his stomach made him realize maybe his body hair was growing in slightly thicker than would be appreciable after all...
Looking around, Jack made his decision...