Seth continued to examine his new body in the mirror. What the hell had happened? He had gone from a short, skinny teen, and now he looked like a high school jock. He didn't have the biggest muscles, but he definitely had some tone and definition. He even had a visible 6 pack when he flexed! He looked down at his cock. It hung down, soft, pointing down to the floor. It had to be at least 5 or so inches long now, and his balls looked a lot bigger. They hung down a bit lower in their sac. Likewise, he had a small bush of thick brown curly pubic hair above his crotch. This seemed to be the only body hair he had now, but before this he didn't have any! He reached down and cupped his now fatter nuts. As he did that, he felt a pleasurable rush go through his groin, and Seth let out an involuntary moan. Even his voice was deeper, he noticed! He slowly felt blood flow into his newly enlarged jock member; he was getting horny and hard! Having never experienced this feeling before, he didn't know what to do. It felt like a deep ache, a deep need, to do something with his cock.
He had heard about jacking off before from some of the boys at school, but he had never actually done it before. He looked down and saw his member was rock hard and sticking straight out. It was throbbing and begging to be touched. A glob of something sticky was dripping off of the tip. "Whoa, it's so much bigger than before...", he muttered to himself, still surprised at how his voice had dropped recently. He took his hand and wrapped it around his cock. "Fuck", he said, amazed at the sensitivity and the wonderful sensation his touch caused on his cock. He closed his eyes, and it was almost as if instinct took over. He began pumping his muscular arm up and down, like he had done this a thousand times before.
The sensation was incredible. He put his left hand to brace himself against the mirror and really began pounding his meat with his right hand. Having never really been horny before or had a sex drive, these sensations were new to him. He moaned and groaned, and his cock drooled a steady stream of precum all over his hands and the floor. Images and thoughts raced through his mind; hot guys, muscular guys, hairy buff guys dressed in football gear and jockstraps. He was surprised he was thinking about guys; he wasn't gay, was he? It didn't matter; he was so horny he couldn't stop. By now, he had made so much precum it had lubed up his cock. It was making a squelching noise as he jacked off. All of a sudden, he heard a deep commanding voice in his head; "Give in. BECOME A JOCK. A BIG HAIRY DUMB JOCK". He opened his eyes in shock at the voice, but he was already too far gone. He was past the point of no return and his orgasm had already started. He cupped his much larger balls with his left hand as he felt them pull upwards. "UUUHHHNNNNN", he groaned in his deeper teenage voice. He shot rope after rope out of his cock, shooting all over his muscular reflection in the mirror. 7, 8, 9 ropes! It just kept coming out. After the 10th or 11th rope, the orgasm died down. Seth let go of his cock, which made a soft splattering noise as it slapped softly against his thigh. His large balls no longer felt so full, for no at least.
Seth was panting, still in the afterglow of his first orgasm. He started to take some toilet paper to clean off the mirror when he noticed something. When he raised his arm to clean the mirror, he saw a flash of something dark under his arm. He lifted one of his muscular arms. "Whoa!", Seth sputtered. He had armpit hair?! When had that grown in? He had never had so much as a single hair before. Looking in the mirror now, he had a big brown bush of hair sticking out. He felt the hair with his fingers and noticed they felt quite thick and they were very long. he put his arm down and noticed that the hairs stuck out even when his arms were still down at his sides. While looking at his newly hairy pits, his eyes drifted to his biceps. Did those look a bit bigger? He saw a couple big veins racing down his forearm. He still had lean muscle but it perhaps did look a bit bigger. What was going on? With his arms raised looking at his pits, he saw they were a bit sweaty from the workout he just got from jacking off. A musky, locker room smell was emanating from his pits. Uggh, he didn't want to be a smelly teenager, like the jocks at school! He gave his pit a small sniff. He didn't smell that bad, but it was certainly on the way to becoming BO. He would have to get deodorant or something!
Looking down at his crotch, he for sure could see more hair than before. His modest bush had now spread into a thick bushy triangle that led all the way to his waistline. The triangle tapered off and created a thick line of hair, about an inch across, that led up to his belly button. The dark line bisected his newly formed lower abs. He gently fingered this new treasure trail in awe. This was totally new as well! His gaze went up his torso and he what he saw startled him a bit. He had about 5 or 6 brown hairs growing in between his two lean pecs! "Whoa, I have hair on my chest?", he said. Their were not many hairs, but they were thick and dark; you could see them in the mirror. Likewise, he had a few curly hairs growing out around his nipples, too! As he experimentally pulled on the thick nipple hairs that had recently sprouted, he felt a stirring in his crotch. Oh no, was he getting hard again? This was too much, what the hell was going on with his body? Why was he changing like this, getting muscles and hair??? And how was his cock getting so big???
Little did he know, his father was spying on him. He had listened through the door and heard the whole things. He heard Seth jacking off and talking to himself about his changes. His father smirked; "Excellent, the Jock Jacket is working very well... It won't be long now until Seth is a hulking jock!"...