3| Sweat (Changbin)

Soori's boyfriend, Changbin, loves going to the gym. He likes to work on his body and exercising a lot makes him feel good. He's been trying to convince her to join him at the gym for ages but she was too lazy to go, giving excuses that her dance practices were enough exercise already.

But recently she started struggling with a new choreography due to a lack of stamina. Her body just couldn't keep up with the fast beat song, her legs would give out and she would completely run out of breath in the middle of it. This only with the dancing part, singing too would be just impossible and she doesn't like lip-syncing her songs on stage.

So she gives in to her boyfriend's endless requests to go to the gym with him and starts exercising too. But since their goals are so different they didn't manage to match up their workouts and she ended up getting a personal trainer to help her out.

It has been a few months since she started and she is beginning to see some good progress, working diligently to improve herself. And now that she is getting more used to exercising, her trainer decided to add some strength training.

Coincidentally, Changbin is also working on strength training at the moment so they can finally match up a session together. However, because they are both idols, they can't be public about their relationship, so they need to act discreetly at the gym.

The fluorescent lights in the room make the colorful stripes on Soori's windbreaker jacket glow as she stretches in front of the large mirrors, getting ready to start working out.

Changbin came with Han and Chan, and the three of them were discussing their rotation on the machine, deciding what weight they would use and how many reps they would do.

Soori and Changbin keep stealing glances at each other in the mirror here and there, trying to contain their smiles and act cool. Once she is done stretching, she fixes her ponytail and meets her trainer next to one of the machines.

"We're still working on your stamina, so you should start with cardio, hop up" her trainer taps the seat of the stationary bike in front of her

"Okay" she climbs on the bike

"Do 20 minutes and don't let your speed drop under 25"

This is an easy exercise so she doesn't need to focus much, letting herself be distracted by Changbin in the mirror. He is doing deadlifts, showing the correct form to the others.

He looks really good while doing it, his muscles bulging as he flexes them, stretching his already tight black shirt. His shoulders look impossibly broad and muscular, making him appear bulky and incredibly strong.

The sight makes Soori's mouth water, she loves his body and how big he is, being almost hypnotized by the way his muscles move and flex beneath his clothes.

Changbin catches sight of her stare through the mirror, seeing her practically eating him with her eyes. A cocky smirk can't help but appear on his lips and he flexes even more, shooting her a tiny wink.

Her face instantly flushes and she diverts her eyes, looking at the small screen on the handlebar in front of her, focusing on the numbers of the display.

Changbin chuckles quietly as he racks his weight bar, enjoying the pink tint on Soori's cheeks, then letting his eyes roam over her body as well. She is wearing tight gym shorts that are now rolling up slightly as she pedals.

He always loved her thick thighs, they look strong and smooth, he likes to lie on them and have her stroke his hair as they chat, placing small kisses on her skin here and there.

But as his eyes linger on her hamstrings, a movement catches his attention. Her trainer got closer behind her, peeking at the numbers on the display of her bike, then resting his hand on the small of her back, saying something he couldn't quite hear.

He frowns as he watches them. Did her trainer really have to touch her like that just to talk to her in the already quiet gym? And why was his hand still resting on her? She is pedaling, there is not a whole lot of assistance she needs.

"Hyung!" Han's shaky voice snaps his attention back to his members

Changbin rushes to his side and helps him rack his weight which he was struggling to do. Han pants tiredly and smacks Changbin for not paying attention.

"Sorry" he mumbles as he glances at the mirror again

Now Soori has lifted her bottom off the bike seat, pedaling as if she were going up a hill. Her hairline is filled with beads of sweat and her face is starting to flush, her legs flexing with the effort.

The trainer's hand isn't on her anymore, but he is still hovering near, saying words of encouragement to her and hyping her up. Changbin tries to look away and focus on his own workout, but he has a hard time ignoring her loud pants and her butt bouncing in those tight shorts right in front of his face.

"You did good" her trainer praises when she finishes, handing her a towel to dry her sweat

She is nearly drenched with it already, it dripping from her chin and running down her neck into her cleavage. Cardio is always a bit rough and makes her sweat a lot but now her blood is pumping and she feels excited to go on with the weights, just needing a moment to recover.

Removing her windbreaker, she stays in just shorts and a sports bra, using the towel the trainer gave her to dry herself a bit. As she is fixing her ponytail once more, she glances at Changbin, seeing him swallow hard as he stares at her sweaty body.

A feeling of satisfaction fills her chest and she smirks, adjusting her clothes, letting her hands linger in strategic places until Changbin can't handle it anymore and has to force himself to look away.

"Ready to continue?" her trainer asks

"Yes sir" she smiles

"Today we're doing squats, it's important to have strong legs for dancing and the key to a good squat is your form" he demonstrates it first

"Like this?" she tries to mimic him

"Almost, just adjust your pelvis a bit" he presses down at her lower back and lower stomach rotating her pelvis to the correct position "And spread your legs more"

A loud sound suddenly echos through the gym, making everyone jump startled and whip their heads to the source of the sound. Changbin blushes and apologizes, picking up the weight he had dropped.

"You alright man?" Chan asks

"Yeah, it just slipped"

"He's just helping her" he whispers

"I know" he mumbles and starts exercising again

Soori keeps watching Changbin through the mirror, concerned that maybe he had gotten injured. But he continues doing the exercise as if nothing happened and Chan nods at her discreetly to reassure her.

"Since you're having an easy time with the squats, let's add some weight" her trainer's voice gets her attention

"What?"

"Hold this" he hands her a large heavy plate

"B-but sir I-"

"You can do it, come on" he pushes down on her shoulder so she squats

She frowns as she tries to go back up, the added weight making it much harder. But she keeps going, trying to finish her set, her thighs burning with each new squat. She needs to bite her tongue to keep herself from loudly groaning at the pain.

"Now on this last one hold for 10 seconds" her trainer pushes her down a bit more

Ten seconds have never felt longer for Soori, her legs shake uncontrollably and she whimpers as she struggles to keep the position. Even breathing was difficult at this point, her core so tight her lungs could barely expand to let in the air.

"That was easy, hold it 10 more" the trainer smirks

"S-sir" her voice trembles

"You can do it" he holds his hand on top of her head so she can't stay up

"Sir, please" she whines desperately

"3... 2... 1..." he allows her to stand up, taking the weight from her "There you go"

"Oh my god" she drops to the ground immediately

"You good?" he chuckles

"You almost killed me"

"Don't be dramatic, you got nice legs, you can handle much more than that, next time you'll hold it for 30 seconds"

He offers her his hand and helps her stand up, guiding her to a machine to start another exercise. Changbin keeps a close eye on them, starting to get a bit annoyed at the way the guy keeps touching his girlfriend and at the things he is saying to her.

"Let's give your legs a break and work on your core" the trainer smiles and hands Soori back the plate "Hug this to your chest"

"Okay..."

"Now put your hips here" he taps a metal bar with a small cushion on it "And bend over"

"Bend over?"

"Yeah, go as much as you can but keep your back straight"

She leans on the soft cushion, hooking her knees on another piece and then bending over slowly to do the reverse sit-up. It's harder than she expected, going down is fine, but getting back up makes her whole body shake.

Her abs are burning painfully before she even reaches 5 reps and she is supposed to do 15. The sweat drips from her face onto the floor and she can't hold in her groans, grunting loudly with each rep.

"Tighten that core and bend over more, your butt needs to work too" he places his hand on her lower back pushing her down and making her whimper

"Cho Soori!" Changbin shouts

Startled at his loud and sharp voice she nearly drops the weight plate on the ground, struggling to stand and look at him. His expression is serious, his eyes burning into hers with an intensity she had never seen before.

"Your phone is ringing in the dressing room" his voice lower now but still sharp, "I thought I saw CEO on the screen, you should get that"

"But I turned off my pho-"

"Quickly" he snaps

"O-okay"

"It's alright, take a break" her trainer takes the weight from her hand "We'll keep going later"

She nods and goes towards Changbin who is standing at the door to the dressing room, having to squeeze past him when he doesn't move away. She can feel his gaze burning at the back of her head as she walks inside.

The sound of the door closing loudly makes her jump slightly and she doesn't have time to turn back around before he grabs her and pushes her against the cold metal lockers. He hovers over her, locking her in place with his large frame.

"What the fuck Soori?" he says between gritted teeth

"What?" she blinks startled

"What do you think you're doing out there?"

"I - I" she stumbles over her words, not knowing what is happening

"I'll tell you what you're doing" he leans in to whisper in her ear, his breath tingling her neck "You're provoking the shit out of me"

"Provoking you?"

"Yeah" he starts kissing her neck softly "With that trainer of yours, touching you all the time"

"Bin I'm just working out"

"I don't like it"

"What do you-"

"You're mine" he pulls away a bit and grabs her chin to make her look at him

He glues his lips to hers, forcing hers open so he can stick his tongue in. She takes a few seconds to process the situation but eventually gives in, kissing him back. The kiss is fast and intense, almost violent, and both their lips are red and swollen when they pull away.

"Do you hear me?" Changbin's voice is so low his chest reverberates in contact with hers "You're mine"

He grabs her hips, pulling her lower body closer to his and she can feel something hard poking her through his pants. A small flame almost immediately ignites inside her, getting carried away by the intense situation.

"So how dare you look this fucking hot in front of someone else?"

His hands slide from her hips to her butt, squeezing it and then lifting her up, making her wrap her legs around his waist. He kisses her neck heavily, licking at the hot skin, holding himself from biting it with all his might.

The cold metal of the locker pressed on her back contrasts with her own now feverish body, bringing a shiver down her spine. And as Changbin presses his hips more against her, rubbing them slightly, a quiet moan escapes her lips, desire starting to overtake her.

"You're all sweaty and gasping, with your ass up in these tight shorts in front of everyone, letting that dude touch you and tell you to spread your legs and bend over," he says into her neck between kisses

"I was just working out" she defends herself

"Only I can do that kind of thing to you" he growls "But I won't tell you that, I'll show you"

He releases her legs so she can return to the floor and spins her around, pressing her face and chest onto the cold metal. With one hand he grabs her hair and forces her head down more, with the other he pulls at her hips, making her arch and bend.

Her shorts and underwear are quickly yanked down before he forces her legs apart and lines himself up with her entrance.

"Ready?" he whispers in her ear

Her breath has already picked up a lot, feeling almost dizzy at all the intensity. She has never been this turned on, her entrance is dripping and trembling in anticipation, her body burning with desire. All she can do is quietly nod.

"I didn't fucking hear you" he grabs her hair and pulls it harshly, making her gasp

"Y-yes," her voice is barely a whisper

"Answer me like you answered him" his voice is low and sends shivers down her spine

"Wha-"

"Say: Yes, sir" he pulls more on her hair

"Y-yes, sir"

He then slams into her, making her take it all at once. She gasps loudly and holds onto the locker to keep her balance. With no hesitation, he starts thrusting strong and fast.

His large member reaches deep into her, hitting a sweet spot inside that has her legs trembling already. A moan escapes her lips at the overwhelming feeling and the hand that was pulling her hair is now covering her mouth.

"Be quiet" he whispers "I'd love for everyone outside to hear what I'm doing to you in here but I don't think you want that"

With one hand on her mouth and the other holding her hip, he continues slamming into her, picking up the pace even more. Her back hurts from the position and it's hard to keep quiet even with his hand covering her mouth.

But the excitement of doing it at a place like this, where at any moment someone could come into the changing room and catch them and also the fact that Changbin is being rough with her for the very first time turns her on so much she can already feel an orgasm coming.

Her eyes roll to the back of her skull as the familiar tingle starts in her inner thighs, her entrance throbbing and clenching around him. Her breath picks up even more and her muffled moans make drool drip from his fingers.

As soon as he notices she is getting close, he slows down, wanting to tease her for longer. She whines when the feeling starts to dissipate and tries to turn to look at him, meeting his mocking eyes and his evil smirk.

She is about to complain when the door suddenly opens, making her heart drop. She tries to move to get away but Changbin won't let her go, continuing to slowly thrust into her, going as deep as he can every time, looking right into her eyes as he does it.

"Cho Soori-ssi?" she hears her trainer call her from the door "Will you take much longer?"

She holds her breath and tries to not make any sound. Changbin is still going, his pace torturously slow. His smile just grows more cynical and his eyes turn darker by the second.

"Cho Soori-ssi?" her trainer calls again and they hear him take a step into the room

"Answer him" Changbin whispers in her ear removing his hand from her mouth

"I - I'll be out in a second" she manages to say, her voice weak

"Are you alright? Do you need help?" he takes another step in

"No!" she almost screams in panic "I - I'm ok, just give me a moment"

"Okay, I'll be outside" he walks out and closes the door

"Good girl" Changbin chuckles and starts to fully ram into her again

She gasps loudly so he pulls on her hair, smashing his lips to hers, muffling any other sounds. The kiss is messy at the odd angle, it makes her neck hurt but she doesn't want to stop, just kissing him back with even more intensity.

He feels her moans in his mouth and goes faster, making the tingles return to her legs. The spot he is slamming into repeatedly starts heating up, stealing all her attention, all she can feel is just that tiny spot deep inside.

It feels so good it's blinding. Her body trembles and her legs threaten to give out but Changbin holds her tightly in place, thrusting stronger so they can reach their high at the same time.

Her breath hitches in her throat and she can't control the loud throaty moan that escapes her when the orgasm finally hits her. Her body convulses, her core tightening so much that Changbin feels strangled by it, the pulsing around him making him immediately finish as well.

They take a moment to recover, breathing heavily into each other's mouths, too tired to even move. But eventually, he lets her hair go and carefully pulls out, helping her adjust her clothes once more.

The look in her eyes is a mixture of bliss and tiredness, she looks so beautiful like that, it's his favorite sight. He turns her around and pulls her closer to him, pecking her lips softly a few times.

She holds onto his shoulders as he pecks her entire face delicately before pressing his lips on hers once more, keeping them there for longer and initiating a kiss. This time, the kiss is soft and slow, but just as deep as the previous ones.

She feels a little dizzy when he pulls away, as if she was floating on a cloud. Her eyes open and stare at his soft ones, so different from what they were like before.

"You good?" he asks gently

"Yeah," she smiles weakly

"You sure?" there's a hint of concern in his voice

"I'm not sure how I'm going to finish this workout now, but I'm good" she chuckles

"Do you have to finish it?" he pouts

"Of course"

"But baby-"

"Bin, I'm sorry" she places a finger on his lips to stop him "We'll talk better about this later okay? But I have to go back"

He sighs and lets her go, staring at her back as she walks away and back into the gym. His heart aches at the thought of seeing her with that guy again, even more now after what they did.

Soori smiles at the other members in greeting, trying to play it cool and pretend nothing happened. She goes back to her trainer and they resume her workout, albeit a bit lighter now since she can't handle much more.

Changbin doesn't return, deciding to leave instead. He considers going home but he didn't want to do that before talking to Soori, so he just goes for a walk nearby to calm down and then waits outside for her.

When she is done exercising, she takes a shower and changes at the gym, checking her phone for any missed calls or messages, but not finding any. She was just about to try to call him in concern when she sees him leaning against her car, wearing a facemask and holding a large drink in his hands.

"I can drive" he mumbles when she gets closer, taking the keys from her hand and giving her the cup

"Is this a protein shake?" she looks at it

"Yeah"

"Thank you" she takes a sip after entering the car

"Sure" he gives a cold response and pulls out of the parking lot

He drives quietly with one hand on the wheel and his other arm resting on the window, holding his chin up. His eyes look equal parts angry and sad. The silence is almost deafening inside the car, the tension making the air thick and heavy.

"Bin" she calls him softly "Can we talk?"

"Of course we can" he sighs loudly, running his hand over his hair

"Why are you so worked up?"

He hesitates for a moment, remaining silent with his eyes on the road, trying to organize his thoughts "I'm sorry, I didn't think I would feel this jealous"

"Do you not trust me?" she asks sadly

"I do!" he quickly whips his head in her direction

"Eyes on the road!"

"Let me pull up somewhere"

He parks the car in a quiet street nearby that is practically empty, turning the car off and pulls his mask down, turning to look at her.

"I do trust you," he says with a sad expression "It's just..."

"Just what?" she asks when he doesn't go on

"I just got so angry, seeing him touch you so much when you were like that"

"Like that how?"

"All sexy and stuff"

"Come on" she chuckles and rolls her eyes

"I'm serious! You looked so good I couldn't take my eyes off of you for a second, so I couldn't help but notice every time his hands were on you"

"He was just correcting my posture"

"I just had this whole idea in my head of what it would be like to work out with you and it turned out so differently. I mean, you looked just as great as I imagined, but I wanted to be the one touching you and saying provocative things to you"

"They weren't provocative things" she snorts

"You know what I mean, you can make anything sound dirty with the right intention"

"I can assure you that was not at all his intention"

"I know, he actually seems like a great trainer, and that just pisses me off more" he hides his face in his hands

"Binnie" she calls him softly

"I know I shouldn't feel this way" he sniffles

"You can't control the way you feel, only the way you act" she reaches to pull his hands away from his face, holding them and caressing them softly

His watery eyes carry a turmoil of emotions, he doesn't know how to feel or what to think, drowning in his own jealousy and guilt. She unbuckles her seatbelt and climbs over to his side so she can straddle his lap and give him a hug.

"You know I just have eyes for you" she whispers in his ear

"I know" he squeezes her tightly into his chest, burying his face on her neck

"I understand it might have been a bit upsetting baby, but I promise you there was nothing behind it. As you said, I'm yours"

"I'm sorry" he sniffles and she feels a tear fall onto her collarbone

She hugs him tighter, caressing his hair and kissing his temple, whispering sweet words into his ear. He takes deep breaths in her neck, enjoying her sweet scent and letting it calm him down.

The atmosphere in the car starts to clear, becoming light and comforting, she can feel him starting to relax under her so she gently pulls away to look into his eyes.

"Are you feeling a little better now?" she asks caressing his cheek

"Yeah" he turns his face to kiss her hand "I'm really sorry for everything"

"It's okay"

"I promise I won't do anything jealous and aggressive like that again, I know I can trust you wholeheartedly"

"I would appreciate it if you didn't act jealous like that again, but hmm" she hesitates

"But what?" he asks confused

"I must admit the aggressive sex was pretty great, you can do that again" she avoids his eyes and blushes

"It wasn't too rough?" he asks, his hand caressing her thigh softly

"I can handle rough" her voice is barely above a whisper

"I did quite like it when you called me sir" he smirks and his hand runs up her leg a bit more boldly, she forgot she had changed into a skirt after showering at the gym

"I kinda liked it too" she blushes even more

"Did you?"

"It was hm k-kinda hot"

"It was very hot" his hand sneaks further up her leg, going under her skirt "You sounded very sexy"

"You sounded sexy" she finally meets his eyes once more "I liked the way you spoke to me in that deep voice and showed me you're in charge"

"I didn't scare you, did I?"

"No" she leans in a bit closer "You just turned me on"

He smiles and reaches for her neck, pulling her in for a kiss. A sweet and tender kiss. His other hand keeps caressing her thigh, reaching up until the tips of his fingers start to poke under the hem of her underwear.

She shifts on his lap as she wraps her arms around his neck, making him flinch at their hips rubbing together, a quiet moan escaping his lips. Things heat up a bit more and get more intense as their speed increases and Soori's hips start to rock ever so slightly.

But before they can get too carried away, a loud knock at the window next to them makes them jump startled and pull apart from their kiss.

"Ya, you can't do that here!" an old lady scolds them from outside

"S-sorry" Soori quickly climbs down from Changbin's lap back to her seat

Their faces burn red in embarrassment, they had forgotten they were in public.

"Maybe we should go," he lifts his facemask back up and turns on the car

"Yeah" she can't help but laugh

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That's it for now! Let me know what you thought in the comments — I read every single one! And don't forget to tap the star if you enjoyed it ✨ See you next time with Hyunjin 🖤