Backup Costume

“I told you, I don’t do costumes,” Isaac glared at Mitch as he entered into the house. “I just want to have some fun at a party. Alright?”

“No. It’s not alright,” Mitch glared back. He’d dressed up like a little red fox. The costume fit his small lean body perfectly. Even though he was a good half foot shorter than Isaac, he still had a way of asserting himself. Especially as he grabbed Isaac by the wrists and pulled him through the house.

Isaac tried to pull back but found the grip on the much smaller man tighter than he would have ever thought. He knew Mitch didn’t like not having his way, especially at parties. What he didn’t expect was the lengths he’d go through to make it happen. Everyone else at the party seemed to have gotten the memo. Each of them had taken a costume and made sure that it looked good. Or maybe it was them that looked good in the costume.

As Isaac was pulled through the house all he could see were, sexy fireman, sexy policeman, sexy cowboy, sexy lion, sexy construction worker, sexy waste disposal worker. Honestly looking at Isaac, he almost felt like the little guy was dressed up like a sexy fox with tight little denim shorts and a white cut off shirt. Now more than ever, he was happy that he hadn’t dressed up. Never in his life had Isaac seen so many abs or pecs packed into such a confined place. “Since when did you have so many sexy friends?” he asked.

Mitch only smiled as he opened his door and pulled Isaac in. He pushed Isaac on the bed and then went to the dresser. “I knew you’d be such a pain about the costume, so I decided to pick one out for you,” he said. “I hope you like it.” Mitch spun around with just a tiny singlet and pulled the strings tightly.

“Wh-at?” Isaac belted out a laugh. “There’s no way in hell I’m wearing that.”

“Too bad. I told you to pick out a costume. Since you didn’t, I get to choose for you,” Mitch said as he tossed the small garment onto Isaac. “Sexy bodybuilder it is.”

“What?” Isaac laughed at the assertion. “No fucking way.” He pulled at the fabric. But the fabric pulled back. “Wait. What?” Looking down the poser looked like it had made his way through his jeans. Isaac pulled harder, but it only continued to stretch as more and more of it disappeared underneath his pants. “What the hell!?”

Isaac undid the button of his jeans only to find the black waist band was rapidly molding around his hefty waist. “What the hell man!?” He turned back to Mitch, hands pleading.

“I told you to dress up. You could have chose whatever, and I would have made it sexy. But now I get to choose,” Mitch smiled.

“What the—” Isaac tried to stand up, only to find his weight shifting differently than he was used to. His body fell back onto the bed. Every muscle inside of him suddenly felt different. It’d been over a decade since he’d properly used them, and he knew atrophy along with fat were working together to make moving even harder. It didn’t matter how many times he’d told himself he’d go to the gym or start a diet plan; he’d never actually stuck to it.

However, those memories were starting to rewrite themselves. Isaac felt his mind go numb as the new memories formed. Chicken and rice were about the only thing he ate, and he spent hours a day in the gym. Every second, the memories seeped further back into his memories. Day by day, then week by week, month after month, workouts, diets, meal prep, and getting bigger filled his life.

“What’s… Going… On..?” Isaac felt loopy as he felt the new changes. He tried to focus but could only think about his workout from earlier today. He flexed his arm, feeling his bicep tense the sleeve of his plaid shirt. Any room in there quickly disappeared as his arm filled up the sleeve completely. Isaac flexed again. The tension was even tighter. He let out a giggle as he flexed harder. The fabric was rapidly losing. A loud ripping filled the room as it tore underneath his horseshoe shaped triceps.

Isaac rolled around feeling his new body more. The shirt no longer held tightly against his belly, rather it was his chest that was starting to strain the buttons. Little by little the two halves of the shirt were starting to pull apart as two massive pecs started to form. They pushed hard against their confinement, rapidly trying to tear it apart.

Each breath made the buttons strain even more. They couldn’t handle the pressure of the firm muscles growing underneath them. More of his skin started to show between the separating halved until the buttons finally snapped. Isaac let out a sigh of relief as the strain against his body lessoned. One of his mighty hands reached up and massaged his pec.

He couldn’t help but let out a moan as his rough hand rolled over his sensitive nipple. Isaac’s hips lurched as every muscle in his body flexed. Another sound of ripping clothes happened as his pants could no longer hold his massive quads. His waist was fine as the belly faded away into a solid six pack of abs, but with how thick his quads had gotten, the jeans he was wearing couldn’t handle the strain.

“Feels pretty good?” Mitch joined Isaac on the bed. His small little hands rested on one of Isaac’s pecs while the other held his head up just a few inches away from Isaac. “Don’t it?” he taunted the other man, gently twirling the tip of his finger around Isaac’s nipple.

The bodybuilder squirmed under the pressure. It was barely anything, but he better than he had in his entire life. His cock sprung to life. Isaac squeezed the sheets. His toes curled tightly around the remnants of his shoes.

“Looks like someone’s happy to see me,” Mitch gently gliding the tip of his nail over Isaac’s abs, tracing the deep indentions of the muscles. Isaac couldn’t help but snicker as he felt the finger tickle his toned stomach. The finger continued downward, into Isaac’s poser. “There he is…” Mitch smiled as his hand wrapped around his cock.

“Fu-uck…” Isaac’s felt every muscle in his body tighten. The sensation ran through him. Almost like with each stroke and tug was getting more sensitive than the last. He didn’t even notice as it was the only part of him not growing. Rather it was shrinking. The average 6 inch rod he never felt too proud of was rapidly pulling in on itself. Each of Mitch’s strokes were getting shorter but all Isaac could think was how good it felt. Compared to his monstrous sized mitts Mitch’s small soft hands made his cock feel absolutely massive.

Isaac could feel his heart beating faster as Mitch leaned in for a kiss and feeling his other hand run up and down his powerful bicep. The way the other man touched him felt so much better than he could have ever thought. Any other feelings were gone as he fell more into his primal urges. His body was getting into it as his tongue rolled around in the other man’s mouth. Then it happened.

Mitch’s fingers had slid under his balls, slipping fast his taint and into his ass. Isaac couldn’t help it as his hips bucked, cock sprayed into his poser. “Sorry,” Isaac smiled uncomfortably at his lack of control.

“No reason to be sorry,” Mitch smiled, giving him another kiss on the lips. “I have that effect on people. It’s not like you’re the first tonight…” Isaac flashed him a face of jealousy. Mitch narrowed his eyes, but then gave him a playful slap on the chest. “Come on… It’s a party. We’re supposed to have fun. Right?”

“Right,” Isaac repeated back to him.

“Good,” Mitch smiled as he stood up.

Isaac did as well. He posed for the other man. Thick veins bulged out of his skin, covering each and every one of his muscles. Blood pumped faster making Isaac look even bigger than he already had. “You think anyone will notice?”

“You’ve got a lot to look at,” Mitch stood on his tip toes as he kissed Isaac on the cheek. “Now. Let’s party!”