Mark looked after Julie, who was walking away. He would feel no change for some time as his own change wasn't as drastic for some time. He got up, picked up his backpack and headed for the classroom. He usually wore boxer shorts as tight underpants in his waist size were usually too restricting for his package. The class started without Julie and without Mark realizing anything weird happening.
His spread out legs as he was sitting at his desk and the free feeling of his underwear caused him to not make him feel anything what was actually happening meanwhile. The first changes weren't even visible too. There was only weird but not dissimilar to normal internal processes feeling of something pushing and moving within his lower belly. He sat up on his chair a bit and continued with the lecture. There was a slight increase in temperature under his school jacket and t-shirt. His organs continued to move around and make room for a new system to take place and form. A reproductive system. At the same time and rate as it was expanding, his whole dick was losing mass. His almost apple size balls started slowly deflating and their tight skin started getting looser. His penis started begun to withdraw, first the head, then the foreskin. This was slowly happening over at least 20 minutes over which he blissfully made notes of the lecture and browsed on his phone.
He realized some timed passed without Julie coming to class. This wasn't like her as she paid mind to her school records. He reached for his phone to text her and sat up on the chair and rested his elbows on the desk. As he straightened, he clasped his legs together, but the inside of his thighs didn't encounter the usual resistance. His eyes popped as he squeezed his legs together stronger. His member was missing. He felt only empty space where it used to be. It felt perverse. He crossed his legs in discreet try to feel around is what just happened. The things only tightened around what was in his vanished dick.
He felt warm new mounds of flesh there. He felt their hot and new fluffiness as he squished them. He knew that feeling - he felt it with his hands and mouth every time he went down on Julia. It felt very very wrong to now feel it on himself. His face started to show some slight panic but nobody noticed yet. He squeezed few more times as in attempt to come to terms with new reality. 'How could this happen? This cannot fucking just happen' flashed through his mind.
After two or so minutes of calming himself he steadied his hands on his desk and subconsciously stared in the direction of his crotch under his pants and the desk. He knew what he had to do.
He slowly slid his hand into his jeans and under the boxer shorts. First his hand encountered a familiar mound of flesh, still covered in black pubes. He slowly slid his hand along the crotch down. Instead of his usual thick massive dick the flesh continued down and then started to split into two. The whole mound was somehow puffy, hot and a bit moist from the raised temperature in the area.
He bend over a bit as he clutched the whole thing in his palm. 'There's a fucking pussy in my own pants' he realized with definite shock. As he grasped stronger few times, he felt the new a bit electrifying feelings coming from it. He inhaled quickly and and almost jumped a bit.
Newly formed sensitive and charged nerve endings in his new clit throbbed with excitement. His whole hand was holding what was obviously a newly formed vulva, radiating heat. He still felt his original pubes on it too. Not really thinking, but following his need, he stick his middle and ring finger between the fleshly puffy mounds. Even when the outside was moist, what he suddenly felt inside could not complete. His new and hot labia were already flared up and throbbing. So sensitive. He felt around a bit, felling how cramped, warm and slick the inside was. The clit was begging for attention, same as his new vagina inside his new crotch. It was all mentally so wrong but physically felt so real and right.
He sat up on the chair, his hand still stuck in his jeans. 'Fuck,' he thought.