Mischief Managed (Stray Kids Oneshots)

Gym Buddies | Seo Changbin

You and Changbin had always been close. As friends, you shared many interests, from music to food to late-night conversations about everything and nothing. But one thing you hadn't done together yet was hit the gym. Changbin, being the fitness enthusiast he was, had never actually asked you to join him, but when you mentioned you'd been working out on your own lately, his eyes lit up with excitement.

"I didn't know you worked out," he said, a teasing grin forming on his lips. "I thought you were just a fan of the couch and snacks."

You rolled your eyes, giving him a playful shove. "I'm more than just a snack lover, you know. I've got some strength too."

That was all the encouragement Changbin needed. "Alright, challenge accepted! Let's hit the gym together tomorrow. I'll show you how it's done."

You agreed, eager to show him that you weren't just all talk. You didn't know how much Changbin knew about your fitness level, but you were determined to surprise him.

The next afternoon, you both walked into the gym, Changbin practically glowing with energy. He was ready for a workout session, and so were you. The two of you set up near the free weights, and Changbin gave you a quick look over. His gaze was filled with amusement, but also a hint of competition.

"Alright, let's see what you've got. I'll go easy on you," he teased.

You smirked back, feeling a sense of determination building up inside you. "We'll see about that," you replied confidently.

Changbin started with the dumbbells, lifting them with ease and demonstrating proper form. His arms were toned, and his muscles flexed with each rep. You watched for a second before following his lead, picking up a set of dumbbells yourself. Changbin gave you an approving nod, but he wasn't expecting what came next.

You began your sets, pushing through the reps without a hitch. Changbin's eyebrows shot up as you nailed your routine, the weights looking practically weightless in your hands. It was clear now—your workouts were just as serious as his, and you weren't just here to tag along.

"What the hell?" Changbin muttered under his breath, shaking his head in disbelief. "You're stronger than I thought."

You laughed, feeling a rush of satisfaction. "Told you, I've been working hard."

He couldn't help but be impressed. Changbin, who usually had the advantage in these situations, was finding himself surprised at how well you were keeping up with him. As he finished his set, he set down the dumbbells and looked at you, his competitive spirit flaring up.

"You're making this too easy," he said, the smirk on his face turning into a mischievous grin. "You've clearly been holding back, but I think I've seen enough. Time for a challenge."

You raised an eyebrow. "A challenge? You think you can out-lift me?"

Changbin chuckled, walking over to the bench press. "Let's put it to the test."

You were more than ready for that challenge. After all, he had no idea just how much you could handle.

He took his position, loading the barbell with a fair amount of weight. You watched carefully, making sure you kept up with his form. As Changbin completed his set with ease, you stepped up to the bench press, adding the same amount of weight.

"Alright, here we go," you said to yourself, mentally preparing for the challenge. Changbin gave you a mock bow, already expecting you to struggle.

You began, pushing the barbell up and down with solid form. The strain in your arms was there, but it was manageable. Changbin's eyes widened as you completed the set without faltering. It was clear now—this wasn't going to be as easy as he thought.

"You've been holding out on me!" Changbin laughed, clapping you on the back as you finished your set.

"Well, I wanted to make it interesting," you teased. "You really think I'd let you win that easily?"

His grin grew wider, but now there was a sense of admiration in his eyes. "Alright, you've earned some serious respect. I didn't think you'd keep up with me like this."

You shrugged, wiping the sweat from your brow. "You shouldn't have underestimated me."

Changbin's competitive spirit didn't die easily, though. He pushed you to try a few more exercises, each one more intense than the last. But each time you proved him wrong, lifting more, enduring longer, and never backing down. By the end of your session, Changbin was panting, clearly worn out.

"Alright, alright," he said between breaths, raising his hands in mock surrender. "You win. You're stronger than I thought."

You smiled, proud of your unexpected triumph. But there was something more than just the physical challenge that had made this workout memorable. You could tell Changbin was impressed, and you were glad you got to show him another side of you that he hadn't expected. The playful banter and lighthearted competition had pushed both of you, and it felt rewarding to have shared that experience together.

"Guess you're not the only strong one here, huh?" you said, wiping the sweat off your forehead and looking over at him with a teasing glint in your eye.

Changbin gave you a tired but sincere smile. "No, you definitely aren't. I think I'll need to step up my game next time."

"Looking forward to it," you said with a grin.

As the two of you walked out of the gym, Changbin's usual cocky attitude had softened. He had underestimated you, but it was clear that he now had a newfound respect for you—not just as a friend, but as a workout partner.

"You really surprised me today," he said, nudging your shoulder with his.

"You weren't the only one getting surprised," you said, a small laugh escaping your lips.

Changbin's smile widened as you both headed out into the cool evening air, already planning your next gym session together. He knew he had met his match in you, and honestly, he couldn't wait for the next friendly competition.

4o mini