Naughty Swim Instructor (Chicago #6)

After that first time (or times, plural) with Mark, I somehow felt even more insatiable. We continued with sexting and phone sex mostly, out of necessity. But then, Mark started coming by my apartment on his way to and/or from work on days when I was home and had the place to myself, telling his wife he had to go in early or stay late. Sometimes I would end up running late to class or scrambling to switch a shift at work at the last minute, in order to make the timing work. I knew logically that what I was doing was irresponsible, not to mention cruel considering his family, but I couldn't seem to help myself.

One night, Mark offered to pick me up from work at the gym on campus after a late lifeguarding shift. I wondered what excuse he'd given his wife, for why he had to run out so late. Maybe they needed more diapers or coffee or something. I didn't let myself think about it too much, though.

After my shift that night, I walked out of the gym through the revolving door and quickly spotted Mark's car, double-parked right in front, with the flashers on. I smiled and walked over, letting myself in on the passenger side.

"Hi," I said, leaning over the console right away to kiss him.

"Hey there," Mark chuckled against my lips. He pulled back, still looking at the building, checking out the atrium through the enormous windows. "Looks like a nice gym."

"Yeah, it is nice," I agreed, not looking back. I tried again to keep his attention, putting my hand on his chest and tugging him closer by his shirt.

Mark finally gave in, looking back at me and smiling, kissing me and cupping my cheek before sliding his hand over my neck, under my hair. I moaned softly, my hand sliding down and around his waist to his back.

"I've been wanting you a lot today," I whispered against his lips.

"Oh, yeah?" he asked before kissing me again, sucking on my bottom lip.

"Mm hmm," I moaned, digging my fingers into his back as I felt his teeth scraping my lip, his hand squeezing the back of my neck.

"What have you been thinking about?"

"I was thinking a lot about your hands. And your mouth. Just for starters."

Mark moaned, his hand dropping to my thigh and sliding up under my shorts, squeezing my ass right away. His lips slid to my neck, kissing, sucking, and scraping his teeth over the skin along my jaw and below my ear.

"Fuck," I gasped, bringing my hand to the front of his shorts, feeling his bulge and rubbing it. "I want you so much."

Mark stiffened when he felt my hand there, growling against my neck.

Then we got distracted by some sudden motion right in front of the car. I looked up to see a guy leaving the gym, cutting across the street right in front of Mark's car. He didn't seem to have noticed us, but it was a reminder that we were in a very public spot.

I smiled and laughed a little. "Should we go back to my apartment? We might beat Molly home."

Mark smiled back, but it faded quickly. "I don't have a lot of time tonight."

I knew what he was leaving unsaid: he had to get back to his family before too long. The reminder of the lies he must've told his wife on his way out to meet me brought back the guilty feelings I'd been trying to ignore. I quickly pushed them away again.

"Okay," I answered, hoping it sounded casual. "Well, there'll probably be fewer people walking around if we park outside my building. If you have a little time left when you drop me off..."

"Yeah, I think I can swing that," he smirked, his hand still resting on my thigh, rubbing.

During the drive, I continued to tease Mark by rubbing him through his shorts, then sliding my hand into mine to rub my pussy when he started getting too distracted to drive. By the time he pulled onto my street and double-parked in front of my building, I'd successfully driven him crazy enough to grab me, dragging me closer with a hand on my inner thigh, demanding for me to take my shorts off. He fingered me and rubbed my clit until I came, then we got in the back and I straddled him, riding his cock until we both came again.

We came down slowly; kissing, touching, and squeezing more tenderly.

"That felt so good," Mark said, still rubbing my thighs and ass. "I love cumming inside of you."

I smiled down at him. "Me too."

Then, as I kissed him again, Mark held me back gently rather than deepening it. "I should probably go."

And there it was again: the reminder that we were just sneaking around, and he had to get back to his family. I fought to keep my reaction hidden, forcing a smile as I lifted off of him slowly. "Yeah, okay..."

As I lifted off of Mark's cock, we both felt his cum dripping and fumbled to catch it before it made a stain on his car seat.

"Shit!" Mark cursed.

I just laughed, holding the drips that landed on my fingers, looking around for any we might have missed. "I think we caught it all."

"Always such a mess when I'm with you," Mark smirked, his own fingers covered in cum, too.

I smiled and felt myself blushing when he said that, happy to hear him attributing his big reaction to me. Wanting to reinforce that thought, I reached for his wrist, bringing his fingers to my mouth and cleaning them off.

"Mmm," Mark sighed, watching me lick the cum from his fingers, then my own. "You're so sexy. I wish I had more time to stay. You're making me hard again doing that."

"I wish you could, too," I answered, honestly. "It's ok, though. There's always next time."

"I want you to go upstairs and make yourself cum again in the shower. And then you'll cum again when you get to bed."

I smiled, happy to get more directions. "Will you cum again too, when you get home?"

"Yes. I want you to text me when you cum the first time in the shower. That should happen by the time I get home, so you have about fifteen minutes. Then I want you to get in bed naked. I'm going to make you cum again there, while I'm stroking my cock for you at home."

My smile widened as I readjusted my swimsuit and pulled my shirt back on. "Okay," I agreed easily.

Mark pulled his shorts and underwear back up, tucking his still semi-hard cock inside. "I'll get your shorts," he offered, getting out of the back seat first and walking around to the passenger side. He opened the front door first and picked up my shorts from the floor, handing them back to me.

"Thanks," I laughed, slipping them back on before climbing out of the car to join him on the sidewalk.

Mark retrieved my flip-flops too, setting them out on the sidewalk for me before reaching back in for my backpack.

"Such service," I joked.

"I do what I can," he said, winking at me.

I laughed back, taking the backpack from him and thanking him.

Mark looked around the street before leaning in and kissing me again. I struggled not to moan into him, my hand coming to his chest again, holding his shirt gently.

"Remember, fifteen minutes," he said when he pulled back, looking at his watch. "And text me to let me know when."

"Yes, sir," I joked.

We both smiled as he gave my ass a final smack. "Good girl."

"Get home safe," I said, walking towards the building entrance as Mark walked back around the car to go. I got my keys out and unlocked the door. He waited to make sure I was in, and we waved goodbye as he pulled away.

***

As I let myself into the apartment, already thinking ahead to my next orgasm, I was surprised to find the lights on and the sound of dishes clanking in the kitchen. I followed the noise to find Molly cleaning up.

"Hey, how was your day?" I asked casually, mentally preparing myself to keep the conversation short, wanting to meet Mark's time requirement.

Molly stopped what she was doing and turned to face me, giving me a pointed look. "My day was fine. How was yours?"

Shit. I could tell from Molly's tone that she must know something. Had she seen something? I didn't want to give in too easily, just in case I was wrong, so I attempted a casual response. "It was okay... just classes and work, nothing exciting."

Molly's eyes widened a bit as she looked at me, nodding slowly. "Nothing exciting?" she repeated.

I just shrugged and shook my head. "Not really."

"So having sex with a married guy in an illegally parked car right outside our building is just a casual Wednesday for you now?"

Busted. I felt my face turning red, realizing that Molly had apparently walked past the car without us noticing. I wondered how many others could've seen us, too... the thought started to excite me, but I forced myself to focus on Molly and pushed the exhibitionist fantasy out of my mind for the time being.

"I'm sorry you saw that." I replied, not knowing what else to say.

"Sorry I saw it? Or sorry it happened? Again?"

I shrugged. "I don't know."

Molly just stared back at me for a few moments and I could feel her putting together her argument. "It's not a good idea, Sam," she started. "I don't get it. What is it about this guy that makes it feel worth it to sneak around and risk fucking things up for his family?"

My blush intensified as I thought about the answer to Molly's question. All the things I could say that would likely shock her about how things with Mark felt so exciting and turned me on in ways I never imagined. I attempted a lighter version of the truth: "I know it's wrong," I admitted. "I don't know why I'm doing it, I just... There is something about him. It feels like I can't help it, whenever he calls or texts, or offers to come by-"

"So he's been coming by, then?"

I sighed, knowing there was no use in trying to hide it anymore. "Yes. For the past couple of weeks. On Saturdays mostly, while you're at the bar. And sometimes on his way to or from work during the week."

Molly shook her head again. "I know I can't tell you what to do, and I'm sorry you felt like you had to hide this from me. I'm not trying to judge you. I really just don't want to see you get hurt. And it's not like you to hurt anyone else, either."

"Yeah, I know," I answered, feeling the guilt building up fast.

Molly seemed like she was waiting for me to say something else, but I didn't, so she gave in again. "You have to know that it's going to end badly for you, right? One way or another."

I knew Molly was right, and that I might look back at this conversation and regret not taking her more seriously. But I also already knew what choice I was going to make. As much as I could consider it a choice, anyway.

***

I checked my phone as soon as I got to my room, still feeling tense after Molly's confrontation. There was a message from Mark waiting for me.

Mark: I'm almost home. How's that orgasm coming? Getting close?

I sighed and typed out my reply.

Sam: I might need a few extra minutes... Molly saw us

His three dots started moving almost as soon as my message was sent.

Mark: Oh

Mark: Everything okay?

Sam: She tried warning me again to stop seeing you

This time, the three dots started and stopped a few times.

Mark: Think she's right?

Sam: I don't know... maybe

Mark: Is that what you want, then?

Sam: No

Sam: lol

Mark: lol

Mark: That's good

Mark: That's not what I want either

Sam: I figured ;)

Mark: What are you doing now?

Sam: Just got to my room

Sam: Haven't showered yet

Mark: I just got home, inside

Sam: Everyone asleep?

Mark: Yeah, I think so

Mark: What's the name of your gym?

Sam: Why? lol

Mark: I think I found it

Mark: We've been talking about signing the kids up for swim lessons... Don't suppose you have any openings? ;)

I couldn't help smiling widely when I saw that message, instantly excited by the thought of Mark bringing his kids to my gym, signing up for my lessons. All of those built in opportunities for us to sneak off and fool around before or after the lessons. Surely his wife would come along, too. But somehow, even that part felt exciting. I imagined Mark and I sharing secret looks, smiles, winks here and there. But I wasn't sure I'd be able to act casual in that sort of situation. I knew it would be really risky, that his wife could easily pick up on something there.

Sam: hahaha

Sam: I might have an opening for you :P

Sam: Not sure that's a great idea though...

Mark: Probably not ;)

Sam: lol

Mark: Maybe I'll sign up for a membership, too

Despite my concerns, which were weighing a little heavier following the talk with Molly, I was happy that Mark seemed to be set on the idea. Still, I felt like I needed to make sure he was considering the risks of what he was proposing. I aimed to toe the line between caution and excitement, not wanting to turn him off the idea completely.

Sam: There have to be plenty of gyms closer to home for you...

Mark: Yeah

Mark: But I could say someone at work recommended the place

Mark: It's on the way :)

Sam: True...

Sam: :)

Sam: Won't that be awkward if your wife comes for the lessons?

Sam: I'm not sure I'll be able to act casual enough lol

Mark: It could be fun, having our little secret

Mark: Even if you're not able to act casual, she'll probably just think you have a crush on a hot dad ;)

Sam: haha

Sam: Maybe...

Mark: Maybe you can give me a tour next weekend after our first lesson

Fuck. It seemed like his mind was made up, for better or worse. I smiled, getting turned on by the thought of finding a place to sneak off with Mark at the gym, while his wife waited for him, thinking he was on a tour. I knew it would be dangerous for me, too. I could probably lose my job if I got caught hooking up with a dad from swim lessons. But the danger of the situation definitely made it feel that much more exciting.

Sam: Maybe :)

I hoped I could buy myself some time to think things through by not fully committing to the plan. But he'd planted the idea in my mind, and I could feel my body reacting already.

Mark: Thinking about where we might find some privacy?

Mark: Maybe the pool office where you made yourself cum before?

Sam: Probably not during lessons. There'll be a lot of people in and out

Mark: Another office, then? Or maybe a storage closet? ;)

I laughed out loud a little when I saw that message, knowing he was remembering the first time we'd hooked up, in a closet at Sluggers, a bar in Wrigleyville where we happened to run into each other on a night out. That memory caused another tingle between my legs.

Sam: I suppose there are a few options...

Mark: Thinking about it now?

Sam: Yes

Mark: Still wet and throbbing?

Sam: yeah :)

Mark: So hot

Mark: I still want you to make yourself cum in the shower

Mark: Use the shampoo bottle again, imagining it's my cock

Sam: Mmm ok :)

Mark: Good girl

Mark: You're such a good slut for me

Fuck. I wasn't sure I'd ever get used to seeing or hearing Mark say things like that. It was such an unexpected turn on, but I couldn't deny how much I liked it. The proof was in the instant throbbing sensation his words caused in my pussy.

I made myself cum again in the shower as instructed, thinking about Mark and imagining him using the shampoo bottle on me, before replacing it with his cock. Then I came again when I got in bed, waiting for his call. I thought about Mark and his family showing up for swim lessons on the weekend, and sneaking away afterwards to give him a "tour." I could feel the thrill from the riskiness of it, and that feeling was already outweighing any guilt or trepidation.

***

Mark signed up for a spot in my last group swim lesson class on Saturday mornings. All morning leading up to that class, I kept wavering between excitement and nervousness. When the time came, I felt butterflies in the pit of my stomach as I kept glancing over towards the locker room doors. Each time the door opened, and I saw a familiar family, I smiled warmly and greeted them, feeling the anticipation build.

When Mark and his family finally came out onto the deck, my eyes landed on him right away. I felt a blush rising in my cheeks as I watched him scanning the pool area until he found me, smiling. I smiled back, my blush deepening as I watched his eyes roaming lower, checking me out in my swimsuit. I had to look away then, biting my lip and busying myself with organizing the pool equipment for the next class, then talking to another lifeguard for a moment while I mentally prepared for the interaction. Finally, I took a deep breath and went up to Mark and his family to introduce myself before the class started, as I normally would for any new members, determined to act casual.

"Hi! You guys must be the Smiths?"

"We are!" Mark's wife replied sweetly. "You must be Samantha?"

"I am. Welcome to swim lessons! Is this everyone's first time?" I asked, gesturing towards the kids they were each holding.

"I've had lessons before," Mark joked.

His wife smiled, but rolled her eyes a little.

I laughed a little more than I should have, or normally would have, my nerves showing. I tried to recover by asking more questions about the kids and then rambling on a bit about the logistics of the lessons, knowing that I was probably making things worse, but unable to stop myself.

Finally, I was interrupted as my co-instructor spoke up to the group of kids and parents, starting the lesson.

I was mindful of not paying too much extra attention to Mark's family during the class. Mainly I didn't trust myself not to keep making things awkward. I thought about what Mark had said before, that he might be able to excuse my weirdness by suggesting to his wife that I was just a silly college girl with a crush. Maybe that wasn't so far from the truth. Still, I felt like it would be better if I kept my distance as much as possible.

But Mark wasn't helping. I caught him staring at me (mainly at my boobs) nearly every time I allowed myself to look in his direction. I tried giving him a pointed look to get him to stop, but even that felt risky.

After the lesson, the other instructor and I put the equipment away at the end of the deck. I felt Mark's eyes on me again, looking over as he and his wife got their kids dried off. I wondered if he would still try to go through with his plan to ask me for a tour, hoping that he would.

Once everything was cleaned up and put away, I made my way back to the pool office, drying off and pulling on shorts and a t-shirt over my suit. I noticed Mark and his wife waiting around and talking after most of the other families had left the pool area. I figured he was still trying to make the plan work, so I stopped by to chat with them a little on my way out, hoping to open up an opportunity for him to ask about the tour.

"How was the first lesson?" I asked as I approached them, standing near the locker room doors.

"I thought it was great so far, thanks," Mark said, winking.

I smiled, making a point of looking at both of them as I answered. "Good, I'm glad you enjoyed it!"

"The rest of the gym seems really nice, too. I might be interested in a membership. Do you think you might show me around a little?"

Before I could answer, Mark's wife chimed in. "Stop pestering the poor girl! I told you, just ask at the front desk. I'm sure someone out there could give you a tour."

"It's fine," I said, not sure where my boldness was coming from. "That was my last lesson for the day, so I have some time."

"Great," Mark grinned. Then he turned back to his wife. "Do you want to get the kids ready and wait for me at the cafe?"

The wife looked and sounded unsure as she agreed to Mark's plan, but she didn't object.

I knew we were being too obvious about everything, and we should try harder not to act suspicious. But I also felt overcome with the need to get Mark alone as quickly as possible.

I'd already devised a plan for where I would take him, if things worked out. So as soon as the wife took the kids into the family locker room, I led him down the hall and out into the atrium.