I was a 10 years old blonde boy. Pale skin, 5'1" of height and no visible muscles. Of course, as a prepubescent kid I had no body hair except on my head. That's why some people think I'm underdeveloped but I'm fine with my body and I know eventually I'll get more "manly" characteristics. I'm in no rush to grow.
Usually, kids don't like babysitters but I'm not like them because my babysitter is my uncle Eric, an awesome stuntman who had worked on tons of action movies. He has been a superhero, a soldier, a ninja, etc. and he always brings cool stuff to show me. I like to play video games with him, skateboarding and a lot more of things I normally can't do because I don't have brothers or cousins.
Back to the present, I was playing with my dead grandfather's watch when uncle Eric was coming in my house. I didn't know that something unusual is going to happen but he knew and when he noticed what I was doing he dropped the ice cream cone he bought for me and started to run towards me. Unfortunately, he wasn't fast enough and a sudden blast came from the watch and threw us up in the air. After that I got unconscious.
“Are you alright, buddy?” My uncle asked me as I recovered my senses. I was laying on the couch and uncle Eric was watching me from above. He seemed fine, definitely he was more used to explosions than me. But he had taken his denim jacket off and had put it on me. “I need you to tell me exactly what did you do with that watch.”
“I... I” I stuttered because I can't fully process what had just happened, why my uncle was so serious or how much time I have been unconscious. “I tried to turn back the time. It was on 8:30 pm and...”
“8:30 pm?” My uncle interrupted me. “So, we don't have too much time. Quick! Take off your clothes!!”
“Wait. What?” I asked thinking he was joking but he seemed too serious for that. However, I won't take my clothes off without an explanation. I don't have a problem with being shirtless in front of him but I won't undress unless it's really necessary.
“Didn't you hear it? Come!” He shouted at me as he started to undress himself. I still don't comprehend what's going on but I started to take my pants off. “It's no necessary you take your underwear off, for now. I don't want you think I'm a pedophile or so, but you should take your shirt and pants off, and maybe your sock too.”
“Uncle Eric, what's happening? Why are we undressing? What is that watch?!!” Now I was desperate for an answer but he didn't tell me anything and he kept undressing until he was wearing just his boxers. It was the first time I saw him like that. He was well-built with big muscles everywhere, a broad hairy chest and thick leg... Oh my god! He's taking his boxers off!!
“Uncle Eric!!! What are you doing?!!!” I screamed at him but he didn't care and kept pulling his boxers down until I could see his big and long penis hanging freely between his legs. His hairy testicles bounced for a while and they did it again when he left his legs to take his boxers out. I can't believe what I was seeing. My uncle was completely nude in front of me. It was the first time I saw an adult naked! It was the first time I saw someone else's dick!!
“I'm sorry you're watching me like this. I know it can be shocking the first time but I needed to do it because you're going to get it too” He told me as he sheepishly looked down. I hadn't seen him behave like that befo... Hold on, he said what?!!!
Before I have time to say a word my body started to shake and convulse violently. I can't do anything about but feeling it stretching and growing like if I was made of gum. My small body quickly grew big enough to cover the whole couch and now it seemed small for me. My former petite feet were now coming out as they got big like my uncle's. I can feel my toes elongating, my fingers elongating and... ehem... Something else as well.
“You're doing it good, buddy. You now have the size, but you still need the thickness.” As he said that I can feel my muscles burning, throbbing and swelling like balloons. I was so sore to notice my pecs and abs emerging from my skin, my back broadening and my biceps and triceps bulging until I was as well built as my uncle. My legs were so thick now that one of them fell out of the couch.
“You don't need this anymore. There's nothing to hide now.” Uncle Eric said as he took my tight underwear and tore it off. I barely saw it but I noticed that my small and puny dick now looks like a fat salami, it's tip was now replaced by a thick purple mushroom and my balls have dropped into a very loose but, at the same time, tight scrotum.
“And finally, here it comes the hair.” He said as my pores started to tingle and hair started to protrude from them. Fortunately, it didn't last too long but I'm definitely a hairy dude now. “Now, you look complete.” I was panting too exhausted to say anything and started to pass out again but before I got unconscious one more time I heard my uncle saying so casually.
“I wonder if he's bigger than me.”