"Oh fuck! I'm coming!" Dean moaned in his deeper voice before he and Marco creamed their tight underwears.
"Oh boys! You'd made a mess with your clothes!" Mr Mendes told them as they were lying and panting on the ground.
"I can help them, mr. Mendes!" Troy grinned before he grabbed his friends' cummed boxers and suddenly ripped them off. "Who's the gross monkey now? Hahaha!!"
Marco and Dean recovered themselves only to realize that they were sporting huge erections and a lot of messy pubes around them, just like they were making fun of Troy before.
"Why it's still so hard?" Marco embarrassed said as he tried to stand up while he covered his schlong. "Shouldn't it get soft after our...?"
"Ejaculation." Mr Mendes completed. "And yes, it normally does to a regular teenager but I'm afraid you've skipped so many years that your dick is still.. ehm.. aroused."
"How long do we have to stay like this?" Troy asked. "I have a date after school and I can't hang out with her if I'm looking like a college dude! She'll think I'm a pedophile!"
"Don't worry Troy." Mr Mendes said. "The magic will last until this class is over, so if you want to end it quickly I could get a little help from you!"
"What else Mr Mendes? Isn't it enough to be older and naked in front of the class?" Troy said as he uncovered his erection. "Isn't this enough?!"
"Hmmm... Is it, class?" Mr Mendes asked to the remaining kids in the classroom.
"It's a little disturbing, Mr Mendes." Sanjay, a hindu boy said. "Isn't this illegal? I mean they're nude adults inside of a school and exhibited to a bunch of underages."
"I won't think too much about it, Sanjay." Mr Mendes said. "It'll be fine as long as I have this spell book. I can do almost anything with it."
"Anything?" Giovanni, a italian american boy excitedly asked. "Can you make control them? Obey your commands?"
"I think so." Mr Mendes said while he looked through the book. "There it is. According to this writing I can control the minds of the ones who think with their dicks."
"Think with our dicks?" Troy upset replied. "I'm not a douche dickhead..."
"Penis imperium!" Mr Mendes said and Troy and the other naked men stood frozen like statues. "Formation!" Mr Mendes shouted and they make a line like soldiers. They didn't try to hide their erections which were rock hard all the time. "As you can see, as you get older you start to think more with your dicks. That's because of the raging arousal you get by your hormones."
"So, their minds are in their dick now?" Sanjay asked.
"Kind of, in fact let me demonstrate you." Mr Mendes said. "Troy can help us with this."
Mr Mendes threw a spell on Troy who slowly began to get younger again. His height drastically decreased along with his muscles. The hair on his body sucked inside him until his armpits and crotch's bushes disappeared. His feet lost some sizes and finally his dick turned into a pathetic kid's junk with a lame pair of marbles under it.
"What, what just happened?" A confused Troy asked. "I felt like my mind was on a roller coaster."
"There it is." Mr Mendes said. "As Troy's dick has become underdeveloped again, he can't feel any of the adults feelings through his genitals. His male organ only function in this age is just urinating."
"Hey! I'm not a baby!" Troy complained.
"Of course, you're a big boy!" Mr Mendes said and Troy began to grow back to adulthood. His height suddenly increased and his feet duplicated their length. Muscles appeared all over him along with his body hair. Troy looked displeased when he saw that his armpits were full of hair again.
"Oh, come on!" He complained when he saw the bush regrowing on his crotch and when the growth arrived to his genitals and his dick and balls pumped to their adult sizes, he stopped complaining and stood still like the other men behind him. His fully grown up dick grew to its fullest when his erection took it position like if it has a life of its own.
"Ok, Sanjay." Mr Mendes said. "Time to grow."