12 year old Alex was holed away in his room, completely oblivious to the intense sex happening just down the hall in both of his siblings' rooms. Slouched in a chair and totally absorbed in a video game, he didn't even notice as the changes Katie made to their dad started to trickle down to him as well.
Like his brother (used to be), he was one of the smallest boys in his class at about 4'5, but before long, Alex subconsciously shifted in his seat to give his slowly lengthening limbs more room as his height crept up. His feet inched bigger and he briefly missed a button on the controller as his hands grew to match his new stature before his mind had a chance to readjust his new size. Before long, Alex's height levelled off at 5'3, already taller than some men despite being at the cusp of puberty.
Soon after, the still oblivious Alex's musculature began to shift. The remnants of his baby fat melted away leaving behind lean muscle. While he wasn't capable of putting on serious mass (yet), his body spoke to more than just middle school athletics. Whereas his classmates who played sports had the trim and skinny frames of typical tween athletes, Alex had the beginnings of some real musculature that could only be achieved with dedicated weight lifting. His small but defined pecs sat above an already impressive set of abs and his modest biceps flickered into relief as he mashed the buttons on the game controller. His narrow shoulders were just starting to round out with muscle, hinting at what was to come. Alex's slim musculature looked primed for packing on some major mass as he got older, and if his brother and dad's genetics were anything to go by, he most certainly would.
Unlike Jake, Alex's hair darkened to a rich black, much like Katie's and their dad's, but his eyes lightened to a piercing blue, accented all the more by the darkness of his hair, which shortened into a spiky cut similar to Jake's.
As the physical changes slowed, the mental changes began to take hold. Memories of towering over his classmates and nicknames like "stringbean" quickly replaced old memories of being teased for being short. The countless afternoons of doing nothing but playing videos games every day now had regular gym sessions interspersed between the video games. Alex idolized Jake and secretly wanted to be even bigger than Jake some day, so he often tagged along with Jake to the gym, and Jake was happy to help his little jock-to-be brother.
Alex's clothes shifted into a set of loose hand-me-downs from Jake, a gift he resented at first but quickly changed his stance on when Jake jokingly told him to think of them like a goal to grow into, which Alex took to heart.
His room became messier as gym clothes, more hand-me-downs and a few soccer uniforms with his school colors on them were strewn about his room. Another memory of joining the soccer team because his middle school didn't offer football formed. Alex had every intention of playing football in high school like Jake and his dad, though.
The casual strategy game he was playing suddenly shifted into a football video game as his interests in sports and video games began to overlap. Alex was now leaned completely forward, laser focused on the game as the competitive jock side of his personality took over and the last remnants of the old Alex were wiped away without old Alex ever even noticing.
Just as his game was over, his phone rang and his friend and soccer teammate Ben called and asked to come over, which Alex quickly agreed to.