Naughty Swim Instructor (Chicago #6)

I felt Mark's hand on the small of my back as we navigated through the crowded area.

"So hot seeing you in swim instructor mode," Mark said in a low voice, leaning in close.

I smiled, blushing and leaning into his light, discreet touch. Then I spoke up in a louder voice, playing along with the tour guide role. "So this is the atrium. As you can see, there's the cafe over here, and some games by the windows: shuffleboard and ping-pong and things like that. You can check out the equipment at the front desk if you ever want to play. Then over on the right there are the racquetball courts. You can make a reservation online for those, or just ask at the front desk..."

I glanced back at Mark and noticed a smirk. But he played along, asking some follow-up questions and following me across the lobby, then up the open staircase to the second floor, to the main workout area.

I felt the tension building as I showed Mark around the different areas of the gym, knowing he was looking around and evaluating different spots, looking for one that would work for us to sneak off and hook up.

Finally, when we reached the fourth floor, which was a running track that overlooked the basketball courts on the floor below, I looked around to verify that the coast was clear before taking Mark's hand and leading him around a corner to a small alcove by the elevator.

"What's back here?" he asked with a smirk.

"A hiding spot with a view," I answered, gesturing out the windows to the city view.

I watched Mark admiring the scenery and looked around to check that the coast was clear once more before sliding to my knees, wanting to be ready when he turned back around.

Mark smiled when he turned back and saw me like that, his eyes trailing down my body as he stepped closer. "Naughty swim instructor," he teased, reaching to cup my face as he stood in front of me, his thumb brushing over my cheek.

I smiled and reached up to rub him through his swim trunks. "I think that's why you picked me."

"Mm hmm," Mark moaned as he watched, his hand sliding back into my hair, behind my neck.

I felt his cock growing through the trunks as I cupped my fingers around him and stroked, rubbing my thumb over his head. "I want you," I said simply, looking up at him, into his eyes.

Mark closed his eyes, his hands coming back around to cup my face, thumbs brushing my cheeks. "I want you, too. I want to feel your mouth on my cock."

"While your wife waits, down in the lobby," I added, tugging at the drawstring to his trunks and reaching inside, pulling his cock out, fully hard and leaking pre-cum already.

Mark groaned, both hands combing into my hair and tugging.

He tensed up as my hand wrapped around him, a growl vibrating through him. I leaned in right away, licking and wrapping my lips around the head of his cock, tasting his pre-cum and moaning. I kept stroking and sucking, sliding my mouth further onto his cock, knowing we had to be quick.

"Fuck, that feels so good," Mark moaned.

His hands guided my head, controlling the pace of my mouth on his cock. I felt him using his grip on my hair to slide me back and forth, and then his hips were thrusting, too. I reached up to play with his balls as the head of his cock pressed down my throat. Instead of letting up when I gagged, he pressed my head down harder and pressed his hips into me further, groaning.

Then Mark stepped back suddenly, reaching down and pulling me back to my feet. He kissed me and backed me up against the wall, pushing my t-shirt up and squeezing my breasts through my suit right away. I helped to pull them out, and he dropped his mouth to them immediately, squeezing and rolling his tongue around each nipple.

Then he pulled back and flipped me around, reaching around to untie my shorts and slipping his hand inside, rubbing through my suit. He took a step back and pulled my hips with him, grinding his cock against my ass as he pushed down on my back so that I was leaning forward, bracing myself with hands against the wall.

"I want to cum inside you," he said, pushing my shorts down and dragging my suit to the side, exposing my pussy.

"Fuck," I moaned, bracing myself to feel him thrusting into me. I turned around to watch as he stroked his cock, slapped it against my ass, then rubbed the head along my slit.

"I've been thinking about you so much the past few days," I breathed. "Since you came over the other day before work. It's so hot that you came here and signed up for my swim lessons. And that you'll have a membership now, to come by all the time." I felt the grin spreading over my face as Mark pressed the head of his cock against my opening.

"I've been thinking about you, too," he answered, pushing into me slowly. "I've been wanting to slide my cock into this wet pussy again."

I pressed my hips back into him, wanting to feel more of him inside of me, moaning and bringing one hand down to rub my clit.

Mark growled and pressed in further until he was filling me, his hips against my ass. "I love making you cum every night in your apartment," he added, sliding back out slowly, then thrusting in hard again. "Texting you, calling you, making you touch yourself."

"Fuck.." I moaned, rubbing my clit faster as Mark continued thrusting.

"But I want to feel you more."

"I want more, too. More of your cock inside me like this..."

"I love knowing how you never close your blinds, so anyone in the buildings nearby could see in through your window."

"Oh god," I moaned, feeling close already.

"Cum for me, Sam," he ordered, pushing deep inside of me and thrusting fast. "Fucking naughty swim instructor."

"Yesss," I moaned, rubbing faster and harder on my clit. "I love being your naughty swim instructor. I love feeling you fuck me at work, while your wife is right downstairs waiting."

"I know you do. Thinking about her sitting there waiting with the kids while I'm here fucking you. So hot... I love how you always respond to my texts and calls. And I can't wait to meet you here more often. Coming to work out while you work, then fucking you after your shift, before I bring you home."

That was all it took for me. "Oh god, I'm gonna cum!" I barely got out the words before I felt myself clenching hard around Mark's cock, my thighs shaking, my whole body tensed and writhing.

"Fuck, I'm cumming!" Mark yelled suddenly, as I felt the first stream of his cum shooting into me. He grunted and pressed his cock deeper into me as he drained everything inside me.

We both continued moaning lightly, breathing hard as we came down. When I felt him pull back, slipping his cock out of me, I pulled my swimsuit back over my pussy to catch his cum before it dripped out.

"Naughty girl," Mark smiled as he watched.

I laughed a little, standing back up as we both started readjusting our clothes.

"So, did the tour sell you on the membership, then?" I teased, leading him back out to the track, then down the stairs.

"Oh yeah, I'm loving the perks so far," he joked back, giving my ass another quick slap as we reached the landing on the way down to the third floor.

We made our way back down to the atrium, where Mark's wife was still waiting at the cafe with their kids. The nerves came back again, and I felt self-conscious that there might be something she'd notice to tip her off about what I'd just done with her husband. Did we look more disheveled than before? Could she smell the sex? Did one of us have a stain on our clothes somewhere that we missed? But then there was the excitement of feeling Mark's cum still draining out of me, pooling in the crotch of my swimsuit and into my shorts, making me feel sticky. Her husband's cum between my legs. It was so wrong that it felt thrilling.

We made small talk as they got ready to leave. She thanked me again for the lesson, and I told them I'd see them next weekend. As they made their way out, I went behind the front desk to check out from my shift. I kept watching, waiting for a last look from Mark. Sure enough, he looked back one last time and smiled as he held the door for his wife, winking at me over her head. I blushed and gave a little wave as I watched them go.

***

A few days later, Mark came to take advantage of his new membership during my closing shift. He stopped by the pool to say hi and turn me on before heading up to the second floor to work out.

"I'm going to fuck you when your shift is over," he said plainly, his eyes trailing down to my chest, watching as my nipples started poking through my suit and t-shirt.

"I want that," I assured him, breathing harder instantly.

"Think about where," he ordered. "And touch yourself a little through your suit, while you sit in the chair. I want you swollen and throbbing by the time my cock slides into that fucking wet pussy."

"Fuck," I muttered, biting my lip and smiling as I looked around, monitoring the swimmers.

"Naughty lifeguard," Mark said with a smirk as he turned to go.

"Have a good workout. Try not to pitch a tent in your shorts before I can do anything about it."

"I'll try," he winked, heading back out through the locker room.

***

I started cleaning up and shutting things down in the pool early that night, while there were still a couple of swimmers finishing their laps. I'd followed Mark's directions and rubbed my pussy discreetly here and there during my shift, thinking about him and working myself up, getting so excited to feel him that the time seemed to crawl.

A couple minutes before the pool closed, Mark came back, smiling and watching as I put away some equipment across the deck. I smiled back and signaled for him to wait a minute. He nodded and took a seat on a bench casually, taking his phone while he waited.

When I finished cleaning, I made my way back over to him.

"Time to kick them out," he suggested, nodding towards the last couple of swimmers.

I looked at the clock. Just a minute left before closing. "They're usually pretty good about stopping on their own. Not a minute too soon, though."

"No shit," Mark scoffed. "Is everything else cleaned up and done? Just waiting for them?"

"Yeah, everything else should be good," I smiled.

"Good. Did you get yourself ready for me?"

I laughed a little. "Yeah, I'd say I'm very ready now."

Mark smiled back. "Good girl."

Sure enough, the last swimmers finished up then, gathering their things and making their way to the locker rooms. I followed, using my key to lock the pool entrances. Then I made my way over to the lifeguard office to get my backpack, planning on sneaking Mark into one of the full-time staff offices, which would be empty at this hour. He seemed to have other plans, though.

I picked up my backpack from the desk chair in the small, enclosed lifeguard office and turned back to walk out. But before I could, Mark came in and closed the door behind himself, looking at me intently. My chest started heaving as I watched him close the blinds on the windows. I let my backpack drop to the floor as I watched him move closer.

Mark pulled me in and kissed me before I had a chance to say anything. My hands came to his chest as he walked me back a couple steps, moving me to the desk and gripping under my ass to sit me up on it, stepping between my legs to stand right in front of me. I moaned into the kiss and wrapped my legs around him, sliding my hands under his shirt, up his stomach and chest, around his sides to his back, pulling him in closer.

Mark's hands slid up my back and behind my head. He grabbed a handful of my hair and pulled my head back, exposing my neck.

I gasped and moaned as I felt his lips sliding along my jawline to my neck, kissing from one side to the other, over my collarbone and throat, still holding my head back with his grip on my hair.

"Fuck," I sighed, my fingertips digging into Mark's skin as his teeth grazed over my neck. My hands slid to the front of his gym shorts, wrapping one hand around his hard shaft as it tented the fabric, while the other frantically tugged at the drawstring. I was briefly interrupted as he pulled my t-shirt up over my head. I lifted my arms to allow him to get it off before pushing his up and off, too. Then, I reached right into his shorts and underwear, pulling his cock out and stroking.

Mark's hands slid down the line of my suit, brushing over my cleavage before pulling the straps aside, over my shoulders, to the sides of my arms as he kissed down my neck.

I slipped my arms out of the straps and felt Mark's hands take over again, pulling the suit down to expose my breasts, then grabbing them both at once, cupping and squeezing, lightly pinching my small, hard nipples.

I sighed and tightened my grip around Mark's cock as I kept stroking, feeling him tense up as my hand squeezed around him, a growl vibrating through him.

"Tell me what you want," Mark commanded, his mouth dropping to my breasts.

I sighed, combing my fingers through his hair, damp with sweat from his workout, while my other hand continued stroking his cock. "I want you to fuck me right here," I answered easily.

Mark's hands slid down to my thighs, moving up and around to my ass and squeezing, pulling me to the edge of the desk. He tugged my shorts off, dragging them down under my ass. His hand slid between my legs right away, finding wetness seeping through my suit. He pressed his fingers in, rubbing hard before pulling the suit aside.

My chest heaved, and I moaned as he touched me, rolling my thumb over the head of his cock and feeling his sticky pre-cum.

"Tell me to fuck you," Mark ordered.

"Oh god," I whimpered, stroking and trying to guide his cock closer.

But Mark resisted, repeating his instructions again. "Tell me."

"Please..." I breathed. "Please fuck me."

He moved closer, the head of his cock just shy of my pussy. I tried sliding my hips closer to him to close the distance, but he held me in place on the desk.

"Tell me you want to be my slut," Mark commanded.

The words came easily as I felt my pussy throbbing with need. "I want to be your slut. I need you to take me, Mark. I need you to fuck me so much. I'm gonna cum on your cock as soon as you're inside me. You always make me feel so fucking good."

Finally, he pressed in further. I felt my lips separating around the head of his cock as he slid into me slowly. He stopped when just the head was inside, knowing how close I was and smiling down at me as he teased me. I moaned and whimpered, my thighs squeezing around him.

"Please..." I tried again. "Fuck... I need to cum."

Mark's hand slid around to my ass, grabbing and squeezing. Then he pushed forward hard, filling me with his cock in one deep thrust.

"Oh, fuck!" I yelled, the sound filling the small office.

He kept thrusting into me deep and hard, faster and faster. I leaned back onto my elbows on the desk and felt Mark pull me right to the edge, his arms wrapping around my thighs as his thrusts went deeper.

"You like being a slut, don't you?" he asked, his eyes scanning over me, watching my tits bounce as he fucked me.

"Yess," I moaned, my face furrowing with need. "I love being your slut. You make me feel so fucking good."

"I want you to cum," he said, finally. "I want to feel that pussy cum on my cock. Clenching and squeezing."

"Fuck!" I yelped, my hand sliding down to my clit immediately, rubbing fast and hard right away.

"Cum for me, Sam."

"Yesssss," I yelled, my back arching. I felt the pleasure building up intensely, knowing I was going to cum hard, rubbing frantically to get there, needing the release. Then I felt it come over me suddenly, my whole body convulsing involuntarily as the waves of pleasure washed over me. My thighs squeezed together and quivered around Mark as he held them, my toes pointing, back arching up in several spasms. I heard myself yelling out, cursing, moaning.

I hadn't finished cumming when Mark pulled out of me, grabbing his cock and stroking himself hard until he was grunting and cumming in strong spurts. I felt his hot cum as it landed on my breasts and stomach, some making it to my neck. He squeezed the last of it out into my pussy, slipping the head of his cock inside of me again for a couple of last shallow thrusts.

I smiled up at him and laughed a little as I rested back on the desk, cursing again as I felt my pussy throbbing, still.

Mark's gaze burned into me as he stared at my chest, covered in his cum. He reached up to run his fingers through it, rubbing it around my chest and stomach, coating my skin. Then he brought his fingers up to my lips.

"Taste," he ordered.

"Fuck," I muttered, feeling his fingers slip through my parted lips.

Then he pressed his cock forward, thrusting all the way into me again.

I moaned and sucked harder on his fingers as I felt his cock push through my swollen lips. Then I gripped his wrist, pulling his hand back away so I could look down and watch him sliding into me. He pulled all the way out, then pressed in again, moving slowly and filling me completely each time.

With one final deep, hard thrust, Mark stepped back from between my legs, holding and stroking his cock loosely with his fingertips.

"Get on your knees, slut."

That command caused a shiver that started at my neck and ended in my pussy, causing it to clench yet again. I sat up on the desk and then slid off, moving down to my knees in front of him.

Mark's hand came to the top of my head, just above my forehead.

"Good girl. Now clean my cock," he commanded, stepping closer and pressing in to rub the head on my lips.

I sighed and opened my mouth, wrapping my lips around the tip of his cock and sucking gently, slowly. I slid my tongue all over and around his cock, tasting myself and his cum, reaching down to rub my pussy. As I began rubbing and fingering myself again, I felt Mark's cock twitch in my mouth.

"That's it. Finger yourself as I watch, Sam," he said, his hands dropping back to his sides. "I want to watch your cum covered body cum again."

I moaned on his cock, hearing his sexy, dirty words. Still so turned on as I continued to lick his cock. Then I reached up to wipe some of his cum from my chest, bringing it down to rub it onto my pussy, my clit, as I rubbed faster.

Mark moaned, smiling down at me. "Such a good, nasty slut for me," he said with a wink. "Let me hear how wet that pussy is. I love hearing how wet you get for me."

I gave his cock one last lick and then pulled back, smiling up at him and rubbing my fingers from side to side over my pussy, the sloshing sound easily audible in the small office.

"Keep going," Mark said, his eyes moving back and forth between my face and my pussy, watching my fingers rubbing, recognizing my signs as I got close to cumming again.

I watched as he started stroking his cock again, loosely at first, with just the fingertips. He was still semi-hard, getting harder as he watched me touching.

"That's so hot. I love making you cum, and watching you cum for me. I love making you my naughty little slut, Sam."

"Oh fuck," I moaned, getting closer as I listened to his words and watched him stroking his cock, seeing that he was already hard again for me.

"Tell me you're my slut."

"I am your slut. I love being your slut. I love the way you make me feel. How it feels to do what you say."

Mark groaned, gripping his cock a little tighter. "You're MY slut. I don't want you to be anybody else's slut."

Those words sent me over again. I knew I was just a fling for Mark, but hearing and feeling him get possessive over me turned me on so much. Those moments gave me hope that I might be affecting him almost as much as he was affecting me. I came hard again, rubbing over my clit frantically, moaning and writhing on my knees.

"Mmm, good girl," Mark moaned. "You made me so hard. So hot hearing how wet you are."