With a quick tug, Adam yanked down Mario's comically oversized pants. "Let's get you out of these dirty things," Adam suggested, his strong arms making quick work of Mario's shirt as well. Gently but firmly, he guided Mario's smaller form to the floor and knelt at his little roommate's feet.
Mario felt his toes draped in the hot, soft flesh containing Adam's balls. A few minutes ago, they had been 3x normal, and that had been exciting enough. Now, from his still-shrinking vantage point, they were about 5x... meaning he had almost shrunk in half, Mario realized. Adam's cock-cannon stood stiffly in mid-air above Mario's chest. The giant had started to work it with both hands, mostly ignoring its root in favor of the head.
Mario knew that the end result of all this work was going to be more shrinking on his part, and he felt like he should speak up about it. But he was divided, enjoying the sudden -- and growing -- attentions of his hunky roommate. He had shrunk a little more than two feet this time... another two feet might be even more fun. In fact, as Adam slowly continued to gain inches, Mario started to question his own judgement. Adam probably knew best after all. Whether it was the magic, or the sex, or just feeling small and out of control, Mario couldn't really bring himself to protest.
As he was deliberating, out of the corner of his eye he saw movement. With Adam fully occupied with working his dick, Clay was quietly trying to make his escape. Mario felt a little bad for the new kid, suddenly drawn into the middle of this scene. Speaking honestly, Mario said to Clay, "You can leave if you want; I'm sorry we upset you. I really wish that you were having a good time. In fact, I wish you were being given a chance to live out one of your all-time best sexual fantasies." Turning back to Adam's rod and taking his own cock in his hand, he added, "I know I am."
Clay wavered as he moved for the door, stiffling a sneeze from that obnoxious dust he had sat on. This was a total freak show, and yet... as his hand closed on the doorknob, he remembered one time he had jacked off to a fantasy scene that looked kinda like this. Thinking harder, he realized that he had actually had several fantasies with giant cocks and shrinking guys. In fact, he had been visualizing a scene just like this one, off and on, for years. It was one of the main reasons he wanted to come to an all-male school with a reputation for magic. He turned away from the door and back to the scene unfolding on the floor. To think, he was about to walk away from this!
Adam was getting pretty close, and his cock was starting to drip at the tip. He looked down and saw Mario pumping his own little prick, and decided to help out. Leaning back, he said, "Here you go, little guy," and aimed his thick cockhead at Mario's crotch while Mario moved his hands out of the way. Squeezing the end with both hands, Adam milked out several big drops of cum onto Mario's dick and balls. "That should lube things up for you," he said, bringing his own monster back into position above Mario's narrowing chest.
Mario put his hands first on the tip of Adam's giant pole. It was so hot and spongy as he squeezed and rubbed it. He was rewarded by hard throbbing, making the head bigger and less spongy. Almost four feet long, the tip stretched up to his nipples. The coolness as Adam's cum started to dry brought his mind back to his own hardon, and Mario reached down to continue stroking.
He felt the change as soon as his fist closed around his erection. His penis had shrunk substantially hardly a minute after Adam had added the "lube". It was 1/4 to 1/3 shorter already. Reaching with his other hand, Mario felt his lightweight balls. They seemed to be evaporating as he rolled them in his fingers. Soon they would be the size of marbles, 1/2 their starting size. His equipment was shrinking much faster after its second exposure to Adam's cum.
As the implications of that realization dawned on Mario, Adam leaned over, pushing his hard cock against Mario's front. Mario opened his mouth to clarify his wish at the same time that Adam let out a heavy sigh, and his cock unloaded onto Mario. Shot after hot, sticky shot splashed Mario on the face, neck, and chin. Adam leaned back and guided the firehose with both hands, covering Mario from head to toe with his seed. Every nook, every cranny, every hole, and every crevas was filled to overflowing with the creamy product of his giant testicles. Spent, he sat back on his haunches and let his softening cock fall to one side. Looking up, he saw Clay standing at Mario's head. "So," Adam started, "What did you think of that?"
"I," Clay started and then paused, looking again at Adam's oversized sex tools. "I thought that was amazing. And look!" Clay exclaimed, pointing at Mario's sputtering form, trying to clear the hot fluid so he could breathe again.
The little man had shrunken sharply from his pre-ejaculation size of three-foot-something. Having shaken the cum off his hands, and rubbed it off his eyes, he was already less than two feet. He saw Adam's quickly-swelling cock to his side, and gauged his dwindling from the fact that it was now longer than he was. With his fingers, he tried to squeeze the cum out of his ears, and as he shrank past 15 inches, he started to hear the giants clearly. "He sure is shrinking fast this time," Clay said. "How small will he get?"
Mario sat up and tried in vain to shake the cum off his arms. Truth was, he was a total mess. As he shrank, his body collapsed towards its middle, and the cum was bunching up on his arms, legs, and body -- making it thicker, even as he was trying to get rid of it. He looked up at Adam and saw with a start just how big a 36-foot giant appears... especially one with an 12-foot dick attached to his front.
"I don't know," said Adam. "But he sure seemed to be having a great time. Besides, if he doesn't grow back we can always ask one of the professors for some help," he added casually.
Mario stood up, concerned that he needed to make another wish on Adam, and fast. The cum was drying and getting sticky, making his life that much more difficult as his stature reduced further. Finally on his feet, he was planning on shaking his whole body like a dog does when it's wet and then pronouncing his next wish, when he was distracted by the odd feeling between his legs. Specifically, it was the LACK of a feeling he realized. He reached down to feel for his dick as it threatened to go entirely out of reach.
"Well," said Clay, reaching down with two fingers to lift Mario into the air. Unzipping his fly, he said, "Let's put him in here for safe keeping," and with a drop, Mario's four-inch form covered with cum slid down Clay's dick to his balls. This, at least, did more to clean Mario of cum than anything else had, but it did not halt his dimunition.