"Welcome to…..: Mina Ashido's Endurance Weekend!" You could almost hear an invisible crowd cheering as she named their upcoming activities. Mina excitedly bounced around in her newly soundproofed room, confident that nobody would hear her shouting.

One week prior to an important date, the pinky planned out an entire three days of continuous lessons. Izuku had been granted permission to once again try with Uraraka, so in preparation for, and with a bit of growing jealousy, a continuous session of secret lessons was planned out. Under the pretense of endurance training, he accepted without much fuzz.

After their heated second session, Mina found herself wanting an exact repeat of that night. With that in mind, any conflicted feelings of anxiety towards Izuku only grew proportionally to her desire. It was inevitable to imagine him railing his beautiful girlfriend at all times, especially when having first hand knowledge of his prowess in bed.

They would look at each other lovingly in class. They would share longrunning conversations at lunchtime, ones that saw multiple laughs at points. They would hold hands on their way back to class, kiss once on a private spot in the hallway. Every interaction she witnessed brought about a previously unknown pain with it. This growing internal struggle culminated with the news of when the couple would try to have sex again.

Yet, where the flat statement relayed onto Mina by Izuku would have aided in creating more anxious feelings, she took it as an opportunity. By creating a ridiculous event which would serve as smoke and mirrors for her intentions, she succeeded in obtaining more tutoring opportunities. More private time with the green haired boy.

Mina started preparations almost immediately. First, she approached Momo for some soundproof foam. The raven haired girl, knowing exactly why she wanted the item, did not hesitate when creating it. Then, she started to brainstorm their excuses as to why they would be unseen for a whole weekend. Izuku was easy, by claiming a private training session with All Might he created a suitable alibi. On the other hand, finding a reason for herself being absent became a hassle. She contemplated faking illness but concluded that one simple act of selflessness would end their time together. With no fitting excuse for her disappearance, the entire operation was in jeopardy. This continued for two days straight until a brilliant solution reared its head. Dancing classes, ones she had taken before, would serve as the perfect substitute.

The special weekend had arrived and with every base covered, Izuku snuck out on friday night. A green haired hunk with a travel bag showed up at Mina's dorm room door step.

"That's a nice name…" Izuku smiled softly as the door behind him shut. At her instruction, he turned the lock ninety degrees before fully entering.

"Right? Heroes should be good at naming things!" She was nervous, and if she stopped to think for a second then it would show. Ever since their last session, being anywhere near him made her palms sweaty. Nevertheless, she cockily smiled as she spoke.

"So, what is the 'endurance' part exactly?" Izuku, genuinely curious, wanted to know the parameters of what he perceived as learning.

"For starters, you'll be inside me at all times except when eating or bathing." With a straight face, Mina uttered this outrageous statement. The boy next to her was somewhat taken aback yet decided not to question anything, she was a lot more knowledgeable when it came to these things. "There's water over there on the desk, optional condoms inside the drawer and if you really want to… I bought some enhancement pills!" Izuku probably wouldn't resort to those given he was confident in his resilience. A certain choice of words, on the other hand, caught his attention.

"'Optional' condoms?" He scratched the side of his face with a knuckle, seemingly out of nervousness at the possible answer.

"Well I thought a lot about last time." Mina turned around in a swift motion, she started swaying her hips side to side. She grabbed the underside of her shirt with her right hand and her shorts with her left. In nothing more than a second, she was undressed. "You only came once right? Condoms are a restriction, endurance is easy with them."

Beneath her casual clothing was a green micro bikini, tightly hugging onto her shapely body. Her chest was particularly impressive, it was larger than his girlfriends' but still considerably smaller than the biggest in class. Furthermore, the immoral feeling of seeing one of the same colors of her hero outfit presented in such a way granted him an instant erection. Something was off, Mina looked weird,the look on her eye was hypnotizing, a vibe unlike the other lessons was present. Was this her at her most confident?

"I'm on the pill so don't worry about it too much!" She seductively walked over to her desk. After drinking out of one water bottle, she reached for some other thing laying on top of the table. Once she got her hand on it, she walked back over to him. With every single step, her boobs erotically bounced up and down. "How big did you say you were again?" Mina stopped right at his feet. She looked down at the dick protruding through his pants.

"Oh …uh… n…nine inches." Her aura in itself was enough to make him anxious. That swimsuit was dangerous.

"Well, I'm here to check!" Mina rubbed his tip as she kneeled down to check. In her hand was a rather large ruler which she held close to her own face. She pulled his undergarments down to his ankles, revealing an almost fully erect shaft. She carefully placed the measurement object alongside it. "Hmm it does say nine inches but I don't buy it…. Hold on~."

She shuffled forward, her boobs enveloped one of his legs as this happened. Instantly, his member stiffened some more, jumping once at the supple touch. Mina then planted two kisses on the head, followed by her tongue licking the entire length of the underside. It now looked as fervorous as it did on their first time.

"Midori.. You love boobs don't you~?" Her eyes met with his from all the way down on the floor. At this, he looked away, embarrassed. She giggled to herself and gave his cock one last kiss right at tip "Hehe, noted. Let's see here…. 10.4?!" Her captivating eyes widened at the measurement.

"L…last time I measured was around three months ago." He was more worried about the fact that she had caught on to his likeness of boobs than his actual size. He heard some ruffling around with nothing being said for a few seconds, he was still looking to the side as this happened.

"Hey…." Once Izuku opened his eyes, a glistening slit was facing him. Mina, with her spine arched and her hands placed onto the wall, wiggled her hips expectantly. She looked back at him with puppy dog eyes as her tits swayed in unison with her butt. "Agh!"

Izuku, at the sight of her provocative gestures, fully inserted his entire thing inside of her. He relentlessly began pounding her against the wall, earning multiple moans from the girl. The sound of his pelvis hitting her ass cheeks filled the room together with groans of pleasure from both parties. Being inside Mina, unprotected, her insides warmly gripping his dick tightly, and those mounds moving around beneath, immediately made Izuku come close to climaxing. He wasn't ready for this much stimulation at breakneck pace. As so, he started thrusting harder and faster, hopefully looking to drown out the feeling of reaching the climax with Mina's girly moans. This didn't help as he unfortunately shot out his cum deep inside after a few more seconds of love making. The pinky shook a bit once this happened but she seemed otherwise unaffected.

"Ah..ah.. Didn't last too long this time huh~?" Mina, despite feeling intense pleasure, remained collected and teasing. Maybe she was finally getting used to his prodigious technique. "I'll move to a better… position."

It took her a second to turn around whilst still being pinned to the wall. She put her back against it and was now looking directly at his eyes, a sly smile forming. His cum was still dripping out of her folds, making her shiver ever so slightly. Izuku's dick was starting to go limp, and she took notice.

"Here, touch 'em." Mina slumped her shoulders towards him, accentuating her ample chest size in front of his eyes. Her beautiful pair of mounds were within reach. With little hesitation, he began fondling them, feeling every nook and cranny of the sizable orbs. "Looks like someone's awake~." She licked her lips once his cock was back to being fully erect.

Without stopping the fondling, Izuku inserted his dick back inside of Mina, starting over with a slower pace. This time, he adjusted somewhat to the initial wave of ecstasy. He resembled his earlier lessons, where he controlled how the interactions went.

"When you're …. Agh! Having sex, focusing on something external helps you… mmmh… hold on for longer." Her voice was now noticeably breathier as she struggled to stay calm with the puzzlingly rhythmic pumping. He nodded at her teachings.

Izuku kept scraping her insides as he played around with the bountiful mounds before him. After a while, he lowered his head and started vigorously sucking on her nipples. Surprised, Mina bit her own lip once her brain registered what was happening. For a while, this continued all the same. A plethora of sounds escaped her lips at each deep insertion, the hard wood spread apart everything in its path. She was once again going into that euphoric state that she often found herself in. His dick was just too good and his tongue slurping around her tits only aided to push her over the edge for the third time in a few minutes.

"Soooo gooood." No good, Mina already started to slur on her words. She pinched herself hard on her backside, a decision that snapped her out into calmness. If this was to go on for multiple consecutive hours, then she would have to be as lucid as possible. The sloshy sound their connection was making didn't help in any way.

She was about to reach her fourth orgasm of the day when suddenly, another round of cum was relentlessly shot inside. Following a few more pumps, Izuku stopped moving entirely, even removing his hands from her boobs. He still stayed inside her, as per the rules of the endurance weekend. Catching her own ragged breath, Mina began getting ready to speak.

"W…water on the desk… oh?" She was cut off by an unforeseen vibration within her pussy. The boy in front of her had gone into Full Cowling. "What?" Was all she could mutter as she was swept off her feet. He had picked her up from her thighs, carrying her by holding her waist then laying her down on the bed. Not once did he stop being inside of her.

Mina stayed completely silent as she looked up at his determined face, her own countenance gaining a crimson coating. His eyes, though focused on her more outstanding features, were unlike anyone she had ever been with. Not long after this momentous admiration, their activities resumed.

Hours bled into each other as both of them indulged themselves in each other's lust. Somewhere along the way, her bikini was lost to the floor. Moreover, for long periods of time, Mina would be climaxing. Once his quirk was active, it would increase the already incredible pleasure by tenfold. Both of them moaned loudly as they ruthlessly meshed their skin together. They stopped to eat for a while, a heated up cup of ramen each. Even in this innocuous moment, she couldn't bring herself to hold eye contact. Which was weird, up until today she would nonchalantly look at him for prolonged periods of time. Yet, when they finished eating and got back to fucking, she had no problem looking directly into his marbles.

An hour into midnight after multiple changes in positions, speeds, rhythms, they had gotten tired enough to fall asleep. Mina, who had been consecutively riding him for around thirty minutes, bounced her ass onto his length repeatedly. Her head was thrust backwards as a result of the sexual pleasure continually instilled upon her, now being too tired to readjust her position. She was sore in some areas, her waist ached for around two hours now. Though, she wanted to continue feeling his hard pistoning for one last climax. Some yawns even started slipping through both of their pleasurable moans, yet they continued. Eventually, his dick spurted out whatever remained within him, the warmth of it granting the riding girl one final convulsion. She slumped over, exhausted, her eyes already closed and her mind drifting off into nothingness.

Mina awoke with her head resting on Izuku's burly chest. His dick was still lodged inside of her vagina, which was already wet upon waking up. Though disorientated for a second, she gathered her bearings quickly. She looked up only to see his eyes closed. He slept peacefully under her, breathing softly and periodically. A serene feeling washed over her when seeing this angelic sight. She shifted her head back down, looking at his muscles. An earnest smile formed on her face as she began running a hand along his abs. The sensation of leaning against his warm body after their time together was new. This was something she had never experienced, waking up with someone after sex. Maybe it's because it's him…. Huh?

No no no, it can't be, this is just like what Tsuyu was crying about! Just because he has a dreamy body, dreamy eyes, a dreamy personality, soft hands, a fantastic cock… oh. Not heeding Jirou's warning became a grave mistake. Staring upon his broad chest below her, Mina came to the realization that she was already in love with him.

Uraraka came to mind, the supposed reason that this whole thing had started on. She was supposed to take his virginity but Mina intruded on that. In fact, these clandestine meetings that she exclusively set up probably already did irreparable damage to their budding relationship. She unwittingly manipulated Izuku into these, disregarded whatever he was feeling for her own pleasure. Only a horrible person would do that, only someone like her would do that. These feelings toward him should be locked up and thrown away, no matter how much it hurts to do so. This endurance weekend should and will be their last Secret Lesson, for both of their sakes. A single tear rolled down her face, hitting him in the chest.

Izuku was shaken awake by a grinding feeling down in his midsection. Mina was already up, she already had begun resuming their heated interactions from the day before.

"Hey! Hey! Midori! Up for round two?" She beamed from ear to ear. Her sensual movement shook her boobs around, which put him further into full mast. He began thrusting upwards, which also restarted both of their moaning.

This second day was more of the same. At almost all times, Izuku was thrusting inside of her. Some points would see them stop thinking, simply moving in unison with the other's body. Mina's boobs had probably received more attention in these past two days than in her entire sex life, at every passing moment they would be getting played with. If she didn't know better, then Momo would probably be in his thoughts a lot. They ate quietly in between sessions, a moment to regain their stamina and strength before continuing to enjoy the other's body. As the day passed, night fell upon them, and with it came a predicament.

"Oh, it really isn't hard anymore." Mina jiggled his soft dick around to no avail. She planted some kisses on it, sucked the tip, jerked it up and down but nothing came out of her actions. "Hmmm, guess there is a limit." She tried a last ditch effort, placing it between her tits and rubbing it. This was to no avail, as it remained limp.

Izuku, not ready to give up on his training, reached for the drawer and pulled out the so-called 'enhancement' pills. On the back of the case were unintelligible labels for non-doctors, listing off a bunch of random chemical ingredients. Yet, the front was abundantly clear: 'Inhibitors for increased blood flow'. He took out one and swallowed it down with a sip of water.

"Those take around an hour to work by the way~." Mina had stood up off the bed and gone over to her computer. She was still completely naked, with some cum still dripping out of her. It dirtied her desk seat but she didn't seem to mind. "Ooh they finally added Berk. Wanna watch it while you recharge?" Mina grabbed a miscellaneous controller and sat back down on the bed.

"What show is that?" Izuku, a little sore around his legs and hip, sat with his back against the soundproof foam. He looked at Mina's back, as she was sitting right in front of him.

"It came out in 1997 as an adaptation of the Berk manga! Let's watch it!" Mina shifted backward until she was seated beside him against the soundproofed wall. They were inches apart when she pressed the play button. "It's one of my favorites!"

Thirteen minutes into the first episode, Izuku was enthralled. He was accustomed to only watch things regarding All Might and the hero society. This glimpse into the world of Dark Fantasy stories was highly interesting. Mina found herself staring at his concentrated face for most of the episode. It was cute watching him have his entire attention trained on something she also liked. Since this was probably their last night together, she took a risk. Mina leaned over and lovingly laid her head on his shoulder. He didn't react, probably half because of the show and half because they had gotten so used to touching each other's body. Whatever the case, she enjoyed this quiet moment, probably the last of its nature.

Halfway through the third episode, Izuku suddenly stood up with a raging erection. She, looking up at him huffing and puffing, paused the show. He grabbed Mina by her waist and pushed back inside her, overcome by his arousal. An elongated groan of delight escaped from deep within her. A mischievous smirk spread across her face.

"Looks like someone's back up~." As his pumping picked up speed, Mina reflexively bit her own lip. The foreign object seemed to be multiple times harder than before. This time, it quite literally felt like a fleshy rock scraping everywhere inside.

Although he was only just getting used to the feeling of an unbridled hard on, Izuku was able to control himself to a surprising amount. He was expecting to be almost hypnotized, to only be able to restrain his actions with extreme effort. Yet, here he was, witnessing the girl below him squirming like before.

Her lip biting was highly attractive, something he would have trouble accepting. Much like how he dismissed that she looked stunning in that green bikini, he had to lie to himself that the girl receiving his piston wasn't hot. Admitting that fact to himself would open a can of worms that he didn't want to get into. He had to ignore her shapely behind, bountiful boobs, enticing lips, captivating eyes and friendly personality, an easy task right?

The next four hours were a blur, Izuku purposely thought as little as possible, he simply followed the desire to continue moving in a wave of pleasure. Mina was unusually silent as well, she moaned, sure, but her small talk as the time went on became less and less frequent. As the time reached midnight, the effects of the pill started to wear off. Currently, they were in a missionary position, holding hands as they pounded away. Apparently, this was a more intimate manner in which couples could have sex, so they actively practiced it. His cum began rising, feeling like this was today's last shot possible. The watery sound produced by their love making slowed down in frequency as he pumped the final thrust he could for the day.

"Haa… haa.. Yeah… it's late… I'm slee– Hmph!" Mina began speaking when she saw her partner's tired face above hers but was interrupted by a surprise gesture. Izuku had planted a smooch directly on her lips as she spoke. A breach of another ground rule.

His first anal sex on the first lesson, his virginity on the second. In the third session, he took Mina's first kiss. Her mouth had been in many places beforehand, exploring multiple parts of men and women's bodies. It wasn't like she didn't think about it, sharing a kiss with someone, she just never got around to actually doing it. The feeling of intimate connection between them skyrocketed once this happened. His lips were soft, timid even, much like him, and they welcomed hers with open arms. She loved the new sensation, probably more than sex itself. This was tender and lowkey, something that fucking was not. After this gesture, Izuku rolled off of her, already deep asleep on the bed.

She looked at him for a few minutes, her heart pounding wildly. 'What was he thinking' and 'I love him' pounding in her mind. She slowly shuffled her way over and hugged his side. Her head rested on his extended arm, her own hands falling on his chest. The tiredness caught up and her eyes closed for the night.

The next day took an entirely different direction. Mina had no desire to engage in sex immediately. She just wanted to make out for an extended period of time. Izuku was a bit ashamed of his actions last night, but he relented. They sat across from one another, completely naked, with their legs off the bed, their hands holding the other's face. Their tongues explored each other, softly wrestling for control and dancing in unison. Nonetheless, this made Mina so wet that the bed began soaking everything up. As so, they eventually returned to trying out different positions, clashing their flesh together with passionate aggressiveness.

They stopped to eat and at the same time, Izuku wanted to watch more of the show they started the day prior. Mina eagerly put it on, giddy about the fact that he liked it so much. She risked the same bold strategy as the day prior by resting her head on his shoulder. Therefore, most of the day was spent finishing the one season of the show. This broke some of the endurance weekend's parameters but at that point, she had foregone anything to do with the topic, she just enjoyed every lasting second with him.

Then came the unfortunate part of this exercise, the end. Mina did her best to hold in tears, this weekend solidified her dormant love for him. Her heart ached deeply but this result was necessary, she couldn't bring herself to hurt two close friends at once. Every memory that she created with him, she would cherish forever, together with the pain they brought.

"I'll head out first." Mina instructed him to leave a few moments later. In the case that they were caught, it would happen separately. She was choked up, even when opening the door. She would let out her emotions once alone, the bath being a perfect place to do that.

The door swung open slowly. On the other side of it, a recognizable hairstyle came into view. The worst person to be there, at the worst time possible. Those big cute eyes were unmistakable.

"Oh, Mina you're back early!" Uraraka beamed at her as the door shut. She immediately assumed that she had returned earlier than planned, no foul play ever crossing those innocent marbles.

"Y..yeah I did…. I'm… Going to the bath!" She tried rushing out of the conversation, avoiding the worst possible outcome. It was pivotal that Izuku took longer than what she layed out so that these two wouldn't meet.

"Hmmm. Okay!" Uraraka kept smiling from ear to ear. She did little to question why she was sweaty or why her face was weirdly contorted. "Wait! You forgot your clothes inside!" She just had to be so nice. Mina fully expected to return naked and dress back up inside her room, no prying eyes whatsoever. Now she was stuck on whether to rush off without answering and look incredibly suspicious or awkwardly make an excuse to why she was entirely naked and wrapped in a towel.

As she ran circles in her mind, the door slowly opened back up.

"Oh.." Izuku, partly nude, stepped into frame, the door slightly ajar. Everything came crashing down, the weight of reality falling on their shoulders.

"Deku… why are you…?" Uraraka, completely taken off guard, instinctively widened her eyes. Not anger, not disappointment, just surprise.

The three of them stood in that barely lit hallway, silently wallowing in the deafening silence.

A/N

Hey,

I know what to do now, I'm planning three different endings for this fic. This is the nexus point, every chapter from this point on will be a different ending. There's the good ending, the bad ending and the Harem Ending. The Harem ending will probably be two chapters because it couldn't feel natural with one so yeah. This way, I honor my original vision of the ending, my evolved want to do a tragic ending and a newly formed desire for a polyamorous ending. Also, readers can choose the ending they like, so that's a great benefit too.

Tell me how you feel about the multiple endings, like if you think it's a good idea.

One final thing, this chapter ended up being insanely long versus what I originally planned. My writing style is exhausting, I wish I was more concise sometimes.

Have a great day.