Justin toes suddenly bursted out from the top of his shoes. It looks like their feet had grown several sizes and they're still lengthening until they look as long as his father's. James was a size 13, so that means Justin had got 5 sizes.
"What the-?!!" Justin almost cursed when he heard his shoes ripping off but he stopped mid sentence. However James wasn't as careful and shouted aloud "Holy shit!!" while he watched his son's feet getting as large as his own.
"Justin, are you ok?" James asked while he watches the big toes wiggling out of Justin's shoes. "I think so..." Justin replied but something about his voice was off, like it was deeper. "Do you have a cold?"
"No." Justin said but this time his voice sounded definitely deeper like a young man instead of a boy. "Woah, my voice!! I sound so weird!!" Justin was starting to freak out and James knew he has to do something about it.
"Come on. Let's go to the hospital." James put his shoes on and grabbed his car keys. "It seems you're getting an allergic reaction!" He was ready to go but when he turned around he noticed that Justin can't stand up.
Justin began to growl in pain and kneeled while he pressed his belly with his arms. He can feel something going up from his feet to the rest of his body. It was hot and itchy, but it wasn't very painful just really uncomfortable.
However, James can see what was happening to his son. The heat and itch that Justin was feeling was visible through the sudden growth of muscles and hair on Justin's legs. It was like a werewolf transformation from an old movie.
"Holy shit!" James replied while he watches Justin's bones elongating, the muscles on his legs swelling like balloons and the hair on them thickening like a black forest. It looked totally off with the rest of Justin's body.
"Dad! Help me!!" Justin shouted with a voice that James didn't recognize. It seems the growth was still going up, but unlike his legs, James can't see it clearly because of Justin's shorts and t-shirt. "It hurts! It hurts a lot!!"
"Calm down, son. I'm going to take you to the hospital!" James replied and tried to carry Justin but he can't find a way to do it. Also, it seems Justin was getting bigger and heavier by the second. James was panicking right now.
Suddenly, Justin let out a loudly roar and his chest swelled up with big muscles. Pecs that could need a lot of work out and washboard abs that stretched his tank top to it's limit. James fell to the ground on his back.
When he looked at Justin again, he realized that his son was way more bigger than before. His shoulders and back were broader and his chest was covered with a thick pelt of hair. He didn't look like a kid at all.
Justin seems fatigued and was panting with his face looking up and his new long beefy arms resting on the ground. They're still swelling and James can see hair sprouting on them too. They weren't so far from gorilla ones.
James stood up and looked at Justin's face, the only part of him that hadn't changed yet. It was slowly but firmly squaring out, a solid and manly chin with a few hairs that quickly turned into a five o'clock shadow.
"Justin?" James asked when it seemed that the transformation has finally stopped. "Justin?" He repeated but his son didn't move a finger. James started walking around him, still unbelievable to him that he was his son.
Justin was panting and his broad chest was moving along with his respiration. His hands had grown bigger and his already big feet seemed even bigger than before. His facial features had left any trace of childish in them.
"Dad..." Justin said with some difficulty. Despite he said it weakly, his voice sounded manly and imposing. "Dad..." He said once again and began to stand up. It took him a while, because he wasn't used to his new self.
"Holy shit!" James said for a third time when he realized that Justin was almost a foot taller than him now. It seems he weighed at least 100lbs more than him too. And he irradiated masculinity through each pore on his skin.
"I feel..." Justin said with difficulty. "I feel so weird..." He said and James realized that Justin had kept his eyes closed all the time and he hasn't seen himself yet. "I don't know what to say... This is so weird!" James said.
Justin opened his eyes and the first thing he saw was his dad watching him astounded. He had to look down, which was totally weird to him. Like his dad was smaller or so. Then he looked at his arms and it's when he lose it...
"AAAAAAAHHHH!!!" Justin screamed in panic. He had big hairy hands and they were connected to big hairy arms like a gorilla. He was freaking out while he checked the rest of his body. "AAAAAHHH!!!" He screamed again.