Author's Notes:

A commission for anonymous! Thanks for supporting me! :3

So, this was pretty fun to write, and I hope you guys enjoy it!

Disclaimer: Konosuba Copyright Studio Deen (2019)

A PROMISE WELL-KEPT

They did it. They really did it. This awkward group of adventurers defeated the Demon King and brought peace to the world. Through countless, painstaking hours of hard work and leveling up, they toppled the evil power that had held the world in its grasp.

And now, that victorious party was safe and sound at their mansion near Axel.

It could be expected that the leader of that party would be basking in eternal fame and glory in all the popular locales across the land. However, that naïve assumption would be wrong. Kazuma had earned himself a solemn rest; one which he had longed for ever since his peaceful life in Japan had been disrupted by that fateful encounter long ago. This young man had returned to his stubborn NEET ways and had since not left the mansion even a single time. Now rich enough to live in peace and quiet until he died, he ordered everything he needed. Shipments arrived often, however, Kazuma refused to answer the door as well.

Thus, Megumin had taken up the task of watching the door, walking Chomusuke around the mansion, and tending to various household chores. While Darkness assisted wherever she could, the crusader had also left the door duty to the young crimson demon.

The blonde crusader had been receiving proposals all her life, but now that her party had vanquished the Demon King it seemed her value skyrocketed. Noblemen refused to hear a negative response, and the poor woman had to go into hiding with her friends. Yet, even here at this mansion, she was unable to avoid proposals that seemed to arrive every few days.

Megumin was perhaps the most thoughtful of this group. Now that it was just the three of them, there was much to consider regarding their future together. And the thing that most preoccupied her mind was her confession to Kazuma. Not only did she profess her love to the young man, but she'd promised to consummate her union with him.

In other words, Megumin propositioned sex with him.

Ah! The embarrassment at having promised such a shocking thing proved to be too much for her! After all, she was still a virgin. And now that they were back at the mansion, she found she didn't quite know how to handle being around him. When she'd see him look at her, she'd feel self-conscious. Worry filled her mind, on how he saw her and whether she was attractive and mature enough to appeal to his tastes.

However, it wasn't just her own relationship with Kazuma that had caused the mansion to develop into an awkward and tense environment. Darkness had been acting solemn, even depressed lately. So, not only was her relationship with Kazuma strained, but Darkness had been distant with both of them.

Darkness had been spending much of her time shut up in her room. Megumin knew this, and she hated it. After Aqua returned home, it was just the three of them left. She didn't want their camaraderie to fall apart!

With all of this in mind, Megumin hopped off their living room couch. She picked up her cat and held her close to her breast. She took a steadying breath, and then, marched toward Darkness' bedroom door.

She knocked on the wooden panel and waited.

"Y-yes, I'm coming!" called out Darkness from inside.

The clumsy crusader knocked something over in her hurry to the door. When she opened it, her eyes were staring at where Kazuma's head would normally be. And when her gaze lowered, and she saw Megumin standing there, the blonde immediately looked away.

"H-hi, um, Megumin…"

The crimson demon puffed out her cheeks. This tension was so infuriating!

"Let's go into Axel and take a bath together."

Darkness was still looking away, and now her fingers were tapping together.

"I-I, um, I dunno. I'm quite busy, you s-"

Megumin cut her off by grabbing her wrist and yanking her into the hallway.

"Great! Let's go, then!"

As Darkness was pulled toward the mansion's entrance, her cheeks started blushing. She cursed herself for enjoying the harsh treatment.

"M-Megumin! Wait!"

The crimson demon didn't stop, however. Pulling Darkness behind her, she called out to Kazuma as they left through the front door.

"We'll be going out! See you later!"

Neither girl heard his reply as they hurried toward Axel.

"Let me wash your back," Megumin insisted, as she knelt behind her friend.

The girls were at the bathhouse. Megumin had hurried to wash herself just so she could do this. Now that Darkness had lagged behind and was still shampooing her long hair, there was no way to avoid this offer of skinship.

Darkness nodded and went back to her hair. But Megumin could feel how tense her friend's shoulders were as she soaped them up.

"Darkness? Is there a reason you've been hiding from me?"

She felt it was best to get everything out in the open. Even though she felt like hiding inside her cloak, this was something that could go on no longer. It was tearing her up inside.

The blonde froze, and the tension in her body increased. Yet, Megumin's soapy hands still caressed her back, trying to calm the crusader's tight muscles.

"U-um, w-what are you talking about? I-I haven't been acting distant..."

A nagging thought entered Megumin's mind, and it refused to leave.

Slipping her arms around Darkness' stomach, she hugged her from behind.

"You l-love Kazuma, too… don't you?"

She felt the blonde woman tense up, and that was all the answer she needed.

After a few silent moments, Darkness was able to reply.

"I… I thought you'd hate me… for getting between you two."

Megumin squeezed her even tighter.

"I'd never hate you…"

Eventually, the crimson demon let go and finished scrubbing her friend's back. They rinsed themselves off, and then, moved into the heated bath water.

"Actually," Megumin began, blushing, "I made a promise to him, and… I think you can help me out."

Darkness laid back, letting the steamy water ease the tension from her muscles.

"Hmm, what promise is that?"

When she saw Megumin's bright red face, she thought the young girl might be ready to pass out. However, when she heard what this promise was, her face burnt up, too.

Megumin screwed up her courage and knocked on Kazuma's bedroom door.

"K-Kazuma?"

The young man opened his door and looked down at Megumin. The explosion loli was wearing her pink night clothes and had a cute matching blush on her cheeks.

"Yeah?"

The girl looked away from a second, but then, stared him in the eyes.

"Do you remember my promise?"

Kazuma's cheeks tinted pink for a second. Then, he smirked and looked at her figure, from her toes to her furiously blushing face.

"Yes~"

The girl took a step back.

"G-geez, you're incorrigible."

She turned away and started toward her bedroom.

"W-well, come on. Let's go t-to my bedroom."

Kazuma strutted like a rooster as he followed her. He'd been preparing himself mentally for this day, and he was sincerely glad that the moment had finally arrived.

However, once she opened her bedroom door, the young man froze in place. He wasn't even entirely sure if he was seeing things correctly.

Yet, Megumin walked over to her bed and sat down beside Darkness, whom was also adorned with her nightgown.

Kazuma didn't quite know what to think. He looked at the blushing Darkness, and then, he looked at Megumin's burning face.

"Geez! Do we have to spell it out for you!?" the crimson loli blurted out, "We decided it's easiest if we just share you… or something…"

She trailed off at the end, looking away shyly. Darkness looked up at Kazuma, then. Even though she was so embarrassed, she let him know how she felt.

"Yes, we talked things over, and this is the solution we agreed upon. I'm sure…"

The blonde had to look away, clutching her hands to her breasts and squirming on the bed.

"I'm sure a lustful beast like you would jump at this chance regardless," she let out a breathless sigh, "But r-rest assured that our hearts are united on this matter."

"Oh, really?" Kazuma finally replied.

He entered the room and shut the door behind him.

"You're both ok with this?"

He looked at Darkness, and she nodded before looking away and squirming some more. Then, he looked at Megumin.

"Yes," she said, not looking away, even though her cheeks kept burning.

Kazuma shrugged, "Alright."

He slipped his shirt off his body and tossed it aside. Then, he grabbed his pants, and-

"W-w-wait! Kazuma!"

Megumin put her hands out, her lips quivering and her raging blush spreading down to her neck.

"What the heck!? Aren't you going to, you know, work your way up?"

The young man paused with his hands on his belt.

"What?" he asked, "It's all gotta come off anyway, right?"

Megumin was trembling, "That's not the point!"

Darkness was a quivering mess, too. Hiding her eyes behind her hands, yet still peaking at his half-naked body, she started panting.

"I-it's not even been a full minute, and he's ready to pounce on us virgins!"

She gasped as she fell back onto the bed, rolling side to side, trying to contain her perverted joy.

"D-Darkness, now isn't the time!" Megumin tried controlling her.

When she looked back at Kazuma, the man had already removed his pants and was now left in just his underwear.

"K-K-Kazuma!"

The man in question strutted over to the bed, his eyes pinning Megumin down. The young girl leaned back as he drew closer. Her eyes kept flittering down to his underwear that was suddenly pitching a hefty tent in the front.

To be honest, Kazuma was projecting much more courage than he truly felt. He just hoped and prayed that he didn't mess this up and everyone enjoyed this magical first night.

"Yes, my fiery flower~"

He played a suave card.

"Ehhh?" Megumin reeled back, "What the heck!?"

It seemed his attack was ineffective.

Kazuma knelt on the bed, leaning over Megumin. But the girl put her hands out to stop his advance.

"Th-there's a proper order to these things, Kazuma."

She looked at Darkness for support, but the blonde woman was enjoying Kazuma's sudden aggression too much.

Megumin sighed, and then looked Kazuma in the eyes.

"L-look here, we both l-love you. So, you- you should treat us like-" she gulped, "Like w-wives, or something..."

Suddenly, Kazuma cupped her cheek in his palm. They were gazing into each other's eyes. He was leaning toward her. Megumin wasn't pulling away. Darkness watched between her fingers.

Their lips met between them, soft and gentle at first. His hand stroked her cheek before moving into her hair. Megumin leaned into him, deepening the kiss, giving him more pressure. She placed her hands on his thighs to keep herself steady.

They moaned in their kiss. She pulled away to gasp for air, but Kazuma stole her lips again. His tongue worked its way into her open mouth. Not willing to give her a single moment to rest, he stole her breath away with this passionate kiss.

When they parted this time, the girl fell backward onto the bed. Lightheaded, flushed, and her limbs sprawled open, she was an easy target for this man.

However, before he pounced on her, he remembered her stern voice from before. So, turning to Darkness, he grabbed the woman's wrists and pulled them away from her face. The surprised crusader didn't resist as he leaned in and stole her lips for a soft, firm kiss. Then, once he felt her lips part as she tried to moan, his tongue darted forward, conquering a second girl's mouth in the same night.

Once he'd had his fill of her lips, he pulled away. Darkness was panting so much; she couldn't sit up straight. She fell onto her side and watched the two in front of her.

Kazuma turned his attention back toward Megumin.

She considered herself a woman, but she was really still a young girl. And that was made very clear, as the young man pulled off his underwear and revealed his massive length. Bobbing between his legs, this thick and long cock resembled a forearm more so than an average guy's dick.

All that time he'd spent grinding for levels had gifted him with powerful, domineering equipment.

Megumin's throat ran dry. She shivered as she looked at that huge cock. Then, she looked down at her still-clothed stomach.

"There's no way…" she accidentally spoke.

There's no way that thing can fit inside me.

Even Darkness was looking at it with a mix of fear and ecstasy, wondering just how much his impressive girth would tear her up.

Although they were virgins, they knew their equipment could handle a man. But Kazuma's… That thing was a monster…

Kazuma came down onto his hands and knees. His cock was so long it was poking her stomach.

Before she could get anymore afraid, she grabbed his face and pulled him down for another kiss. She distracted herself with his lips and tongue. And when she felt his hands slip underneath her shirt, her breasts happily greeted his rough fingers.

Their lips separated long enough for him to pull her shirt off. Then, they went right back to their kiss. Megumin still felt nervous as his erection kept poking her, but his lips were calming, and his hands felt soothing on her small chest. As he played with her mouth, and his fingers toyed with her nipples, her mind went all fuzzy. Her body was heating up fast. Her legs started rubbing his.

Soon, Kazuma's hands caressed their way down to her panties. Hooking his fingers in the waistband, he tugged them down. He pulled away from her mouth long enough to look at her, as if he were asking for permission. Megumin lifted her hips off the bed, her eyes begging him to go ahead and strip her naked.

The pants were tossed aside, and soon even her panties were lost on the floor.

Kazuma went right back to her lips, and Megumin's arms wrapped around his shoulders. Holding him close, she kissed him deeply. Their moans filled the room. Their passionate heat was even making Darkness feel stuffy in her nightgown.

His hands spread her thighs further apart. The young girl felt tense, but she didn't resist. She was trying hard to keep her anxiety in check because she truly wanted this.

Intent on making penetration as easy as possible, Kazuma's fingers played with her cute pussy. Just like the rest of her, it was soft and smol. His fingers spread her lower lips open, and his middle finger teased her opening. She was wet and hot on the inside.

He continued teasing her for another minute. Then, when her hips started moving, he pulled his fingers away.

Megumin felt dizzy as his lips left hers. But then, she saw him spreading her legs wider, and his monstrous cock was poised to penetrate her.

She gulped, and braced herself.

"I-I'm ready."

She noticed Darkness leaning up to get a closer look. She almost wanted to tell her to look away, but then Kazuma was moving, and she went quiet and still.

His impressive length spread her wet pussy lips open. Kazuma braced himself, and then sunk his tip into her.

Megumin tensed up, groaning, and fisting the bed sheets.

He gave her a moment to adjust. Then, he pushed a little more inside.

It felt like he was tearing her in half. The girl stayed still and tried her best to loosen herself up.

Kazuma eased more of his length inside. He gave her time to adjust between each small thrust. She felt so tight and warm. He wanted to start fucking her…

Soon, he bottomed out. Megumin's eyes grew wide as she felt his tip pushing into her womb. She looked down, and gasped.

There was so much of him outside!

She looked up at him. He was smiling at her.

His dick felt insanely huge inside her body, but finally being connected with him made her forget about the discomfort.

Megumin pulled his head down so she could give his lips a soft, intimate peck.

"I love you," she whispered.

Kazuma's warm smile made her heart skip.

She released him and grabbed onto the sheets again. Then, she nodded at him.

"Make love with me."

He pulled his length out until just his tip was left inside. Her tight walls hugged him; her lower lips tried to keep him inside. His dick was glistening with her wet love.

Kazuma pushed his dick back inside, not stopping until he speared her cervix. Megumin moaned and her hands squeezed the sheets tight. Kazuma strained under the pressure; trying his best not to give in to the temptation to just fuck her but still enjoying her tight sheath so much.

Starting a slow motion, he rolled his hips into her. Slowly making love to her tight, virgin pussy until she got used to him.

"Nnngh! You're so big," she gasped, closing her eyes shut and pushing her hips into his.

That slight movement made his tip push deeper into her womb's entrance. He filled her completely. It was mind-numbing. She'd never have thought her tiny body could fit something that huge inside.

Now that she was moving her hips with his, Kazuma increased his pace. Every thrust made her gasp for air. Suddenly filling her with his massive cock every time his hips slammed down, stole her breath away.

"Y-yes! More," she pleaded.

Kazuma kept increasing his speed until Megumin's bed started quivering.

Darkness had long since removed her own gown. And as Kazuma's thick cock fucked Megumin, her big breasts were jiggling around just from the force of his thrusts. She gasped as she saw the man lift Megumin's legs up…

The crimson demon trusted and loved him. And when he pushed her thighs toward her chest, folding her down, she didn't resist him. When he forced his dick inside, driving all the way to her womb with every push, she gladly received him.

Held down in a mating press, Megumin was fucked like a ragdoll. Moaning and clawing at the bed, and her love-filled eyes gazing up at him.

"Yes! Yes!" she was moaning loudly.

Kazuma moved his hands to the bed, using his hips to pin her down. His speed quickened. Their sex was loud and fast, filling the mansion with lewd noises.

Megumin's hands grabbed onto his wrists. Her parted lips were moaning out his name. He was calling out hers, too.

The unthinkable was happening: his dick was expanding inside her pussy, as it throbbed and quivered.

She saw him close his eyes as he tried to control his passion. So, she squeezed his wrists to get him to look at her.

"I'm close, too," she told him, "So, keep going."

He moved his hips quicker, making sure to thrust his dick in all the way before pulling back out. His weight held her submissive body down. She felt like he was driving her deeper into the bed.

His cock kept swelling up inside her, filling up with cum ready to shoot out into her womb. It was getting harder to move. Her walls clung to him as he fucked her relentlessly. Their sweaty bodies collided; their moans grew louder with every deep thrust.

"Megumin!" he suddenly cried out.

She laid still for him as he slammed his massive length deep into her. His swollen tip pried open her womb's entrance. His climax sent visibly pulsating waves through his cock. Both Megumin and Darkness saw his cock jerk as it shot out gushes of thick cum inside her womb. Kazuma was trembling, and pushing against the bed with his legs, he slid a little more of his dick inside her.

Megumin moaned as she watched her small belly slowly develop a bulge. Her hungry womb devoured his cum. Her wanton pussy milked him for every drop. His dick was unstoppable as it kept filling her up until there was no room left inside, and each new gush of cum leaked out of her pussy.

When he had nothing left to give, Kazuma slowly pulled out of her. The crimson demon girl laid back on the bed with her legs spread and a river of semen flowing out of her.

"Th-that felt amazing," she said with a smile.

Darkness looked at her with wide eyes. Then, she squeaked as Kazuma suddenly grabbed her and held her down.

"You like things rough, right?" he asked her as he used his knees to spread her thighs.

Darkness tried not to moan at the rough treatment, but she let out cute gasps anyway.

"Y-yes! B-but… Ohhh!"

He laid his cock across her pussy. He was so big his tip reached her belly button. Darkness bit her lip. She knew she was smiling lewdly, and she couldn't stop it.

Kazuma leaned down and kissed her lips.

She sighed as he pulled away. Then, she gasped as she felt his thick cock sliding across her pussy as he brought his hips back.

He knew she didn't need anymore foreplay. Even though she was a virgin, she was so wet even the sheets were sticky.

Kazuma guided his tip between her lower lips until he was at her entrance. He looked up at her and saw her lewd smile and blushing cheeks.

"Are you ready?" he asked.

Her hips started wiggling like she was trying to get him to fuck her already.

"Y-yes! Do it! Mess me up!"

It's what she wanted…

So, he shoved himself deep inside on the first thrust. Darkness cried out, the sudden pain of her first penetration feeling so pleasurable she couldn't stand it. With another hard thrust, he buried himself in all the way to her womb.

Although he'd just impregnated Megumin, his heavy balls were already filling up his dick with more cum to shoot out. Darkness could feel his pulsating length deep inside her as he started fucking her hard and fast. She couldn't stand it! The pain and pleasure mixed so deliciously together. His throbbing shaft filled her up all the way with every hard thrust.

Kazuma was giving her everything she wanted!

But then, he stopped moving.

"Wha-" she got cut off.

He grabbed her and, without pulling out, flipped her around so that she was on her hands and knees. She looked over her shoulder at him with wide, lecherous eyes.

"Y-y-you're really going to treat me like a dog?"

She was smiling so wide, and yet that happy expression gave way to lewd moaning as Kazuma grabbed her hips and started fucking her as hard as he could.

"Yes! Harder! Y-yes! YES!" her endless stream of begging was louder than Megumin's wanton moans.

The crimson loli rolled onto her side and watched them go at it. It was amazing that Kazuma had that much stamina; and it was perhaps more amazing that Darkness' high vitality allowed her to take such a savage invasion.

Kazuma slapped her ass cheeks a few times, making the woman moan even louder.

Anyone walking by the mansion would've heard how much she loved rough sex.

He reached around and grabbed two fistfuls of her bouncing tits. Squeezing them roughly while he was fucking her pussy made the blonde crusader scream with pleasure.

Kazuma suddenly felt her walls clamp down on him, and her whole body shook with pleasurable tremors. Her climaxing pussy stroked his length so good it ended up pushing him over the edge with her. Slamming his hips into her ass, he shoved his cock deep into her, penetrating her womb.

Megumin saw it all happen right in front of her. Darkness' body trembling as Kazuma's thick cock rammed deep inside. The part of his dick that couldn't fit inside her was throbbing as waves of cum shot through it. The blonde's tight stomach slowly expanded as her womb took in his semen down to the last drop.

Completely spent, Darkness' face fell onto the bed. But her ass stayed in the air.

As Kazuma pulled out of her only a little bit of his cum leaked out. Most of it stayed inside.

The trio needed a few minutes to calm down. Their first time felt amazing, but it'd worn them out.

However, something was lingering inside Megumin's mind.

"Kazuma?"

"I-I'm Kazuma," the young man replied with a sleepy voice.

"We both l-love you," that word still embarrassed her even after having sex.

"We've both said our feelings to you, but you haven't said anything back. You love us, right?"

Darkness' shaky arms lifted her up so she could look at him.

"You love us, right, Kazuma?"

He looked at both girls. He knew they were talking about a life-long commitment to cherish and love them. But eventually, that would involve having to leave the mansion to help support them.

Suddenly feeling like he had to choose between his precious NEETdom and two cute girls that loved him…

Naked, with his leveled-up cock dangling between his legs, Kazuma ran away from his problems just as he always had before, and probably always will.