After digging through his dad's wardrobe, Frank settled on a large shirt with a cheeseburger on it, and a pair of worn-out jeans dumped in the corner of the wardrobe. Both garments just about fit him, his large chest stretched out the burger design and left the rest of the shirt baggy around his waist, while the jeans struggled to contain his obscene bulge. "Nothing I can do about that..." he thought to himself with a knowing smirk. He took another look in the mirror and grinned at his new adult visage. While he was possibly as old as his dad was now, he was intrigued to see how much they differed. His dad was an average, lanky man with very little body hair. Meanwhile, Frank was a tall and well-built man with body hair to spare. It was clear to him that he took after his mom's side of the family more. While reflecting on his gene pool, Frank noticed something odd. There were a few pinpricks of white nestled within his stubbly beard. Didn't he only have a single grey hair just a moment ago? Maybe he just didn't notice them the first time around...
Before he could investigate further, he heard a knock on the door. Three short raps followed by two hollow thuds. It was definitely George's unique knock. Frank ran downstairs and composed himself, taking a deep breath before swinging open the door. He glanced down at his friend, somewhat surprised at just how short he looked. George used to be the tall one of the two, and now Frank practically towered over him. He cleared his throat and said "Hi George. Don't freak out, but it's really me, Frank".
George stared up at him awestruck, remembering what Frank told him over the phone. But this large, hirsute man couldn't be his best friend, it was impossible! Yet the possibility that it was his friend and not just some elaborate prank was exciting nevertheless. George sighed and asked "OK, if you're really Frank then what video game did you let me borrow last week"
Frank chuckled. "Trick question, your parents won't let you have any video game consoles because they think games encourage violence and stops brains from growing or something stupid like that."
"Woah... Maybe you really are Frank... But this doesn't make any sense! Why are you so big and hairy all of a sudden?"
Frank stepped aside to let George into the house, adjusting his jeans at the same time. Surely his dad had a pair bigger than these. He answered "I really don't know, I just went swimming in my pool for 20 minutes and next thing I know, I look like this. It's crazy, right?". As George head into the living room, Frank tugged on his jean's waistline. Why were they so tight all of a sudden? He conspicuously undid a button and that eased off the tight feeling.
"Totally..." George said, still trying to process that his best friend was now old enough to be his father. That was never something he thought he had to prepare for one day. Could they even still be friends at this point? Maybe if he went swimming in the pool as well, he'd become a man too. But could he really do that?
As if answering George's unspoken question, Frank said "You know, you could totally go and have a swim if you want, see if it really is the pool water that affected me. Then we can be grown-up buddies and do adult things together!"
George almost jumped at the opportunity, until he remembered something. "I really would love to join you and become a man, but my mom's coming back from the shops soon and she'd be real mad if I wasn't at home when she got back..."
"Oh... Yeah, of course..." Frank replied. He really hoped his friend would join him. He scratched his increasingly itchy beard to hide his disappointment. It felt thicker than before, like it had grown in length. But that was impossible, right?
Quick to note Frank's disappoint, George quickly added "But I'll see if I can come back later! I only want to be 15 years older at the most though. You're, like, older than your parents now which is super weird".
Frank was taken aback, and scoffed. "What do you mean older? I look the same age as them"
"Really? Because they don't have white hairs like you. And you got wrinkles on your head like my uncle, and I know he's older than your parents"
Concerned by his friend's words, Frank hurried down the hallway and stood in front of the mirror. The first thing he noticed was his beard, which grown from week-old stubble into a proper quarter-inch long beard. Which made the grey hairs far more noticeable. Well that, and how the minute dusting of grey hairs that spattered his chin had also increased to full-blown white patches that had spread to his cheeks and even the temples of his hair. More worrying was how his forehead seemed significantly larger, as if his hairline had retreated upwards by a couple of inches. Coupled with those forehead wrinkles and some slight creases at the corner of his eyes, he really did look older than his parents now...
Another thing Frank noticed was how the baggy shirt he'd put on was noticeably less baggier than before. His meaty pecs still stretched the fabric tight across them, but now it also seemed his stomach had begun to join them. He lifted it up to reveal a small, solid belly resting over his tightening jeans. It even looked like he'd gained more body hair as it curled and twisted across every inch of his torso, from his pecs and belly to his shoulders and back. Frank had to undo another button on his jeans to ease up the pressure mounting on his growing body. He wasn't obese by any stretch of the imagination but he was much heftier now than he was only a few minutes ago. And the rate he was continuing to grow in both age and weight... Frank turned back towards George with a worried look on his face. "This could be a problem..."