It dawned on the blond that the small boy was picking a fight with him for his mom's love, which only irked him. 

'This kid..!' Atsumu thought as the two glared at each other.

Atsumu heard the quiet snickers behind him, making him turn his head and glare at his teammates only for some of them to have smug looks on their faces.

"Mommy" the two year old spoke up, making the female look at him.

"Yes?" she questions.

"Koji wants watermelon" he grinned, making her chuckle softly and smile.

"Lets go cut some watermelon then." she smiled and ruffled his hair,  making him giggle in the process.

Standing up, she walked over to the men that were sitting with each other while Koji followed her like a little duckling was following it's mother. But the small boy stopped for a moment and turned to look at the blond. 

The two stared at each other before Koji stuck his tongue out at Atsumu before running off to catch up with his mom.

The blond stared at the smaller boy as he was talking to Y/n with a wide smile like he didn't just pick a fight with him. 

This. Was. War.

Although it was childish, Atsumu wasn't going to lose to a child, whether Koji was his son or not. 

"If you don't hurry up I'm gonna eat all the watermelon 'Tsumu!" Osamu yelled to his brother.

Snapping out of his thoughts, he furrowed his brows a bit irritated at his brother. "Save some for me ya pig 'Samu!" he yelled out.

"Hah!?" the younger twin replied.

"Ya heard me!" the twins started to fight which the others only watched in amusement as they ate their watermelon. 

After the small water break, the adults continued to play beach volleyball while Y/n and Koji played in the sand with content. That is, until Atsumu decided to ruin it.

"Miya Atsumu I swear to the gods!" Y/n shrieked as she held onto the blond for dear life.

He cackled as he made his way towards the sea. Before she knew it, she was engulfed in the sea while hearing the sound of Atsumu laughing his ass off. Moving her now wet hair out of her face. She stared at Atsumu who was bent over, clutching his stomach.

Standing up, she shoved him into the shallow water. She stared down at him with a victorious smirk as the pro volleyball player could only blink, processing to what happened. 

Looking up, he grinned evilly and quickly got up before splashing water in her face.

"You-!" she also splashed water into his face which turned into a water fight between the two adults. 

Koji watched with puffed out cheeks, wanting to have fun with his mom as well.

"Hey Koji" hearing the voice, he looked over and saw the better twin (well in his opinion). 

"Hi..." he mumbled, patting down the sand with his paddle.

"Is 'Tsumu being mean?" Osamu smiled and sat down next to the small boy who nodded to his question.

"Yeah..." Osamu watched as his nephew's expression turned into a pout.

"But he hasn't won yet. I'm gonna show him that mommy's all mine" he showed a determined look, which made the male chuckle.

"Why don't we make a big sandcastle for your mom" Osamu looked at the boy who smiled widely.

"Yeah! We'll build a sandcastle thiiiiiiss~ big!" he opened his arms widely, making the grey haired male chuckle and ruffle his hair.

"We'll make it even bigger than that, yeah?" he questions which Koji only nodded his head in excitement. After agreeing on making a huge sandcastle, they started to get to work while also trying to find a crab.

On the other hand with Atsumu and Y/n. The two laughed as Atsumu swung her around. 

"Okay truce!" Y/n laughed out, holding onto Atsumu's arms that were wrapped around her stomach. 

"You're not going to backstab me are ya?" he grinned making her smile.

"I won't I promise" she said.

Before the blond had let go, he gently pinched her sides, making her squeal and pinch him back.

"What happened to truce!" He exclaimed.

"You started it!" she playfully smiled at him until she noticed his expression changed, his face becoming red. Furrowing her brows, she stared at him. "What?" she questions.

He mumbled something that she could quite hear, making her step closer towards him.

"What?" she questions.

"I can see.. your undergarments..." he mumbled, looking away, covering half his face with his hand. 

Her face soon turned red as she hit him. 

"Ouch! What was that for!" he exclaimed.

"This is all your fault!" she huffed out and crossed her arms, trying to hide her now see through dress from the water. 

"C'mon ya had fun, ya know ya did" he grinned as he followed behind her while they made their way to the shore. 

"Shut up..." she muttered, trying to hide her evident smile. 

The boys looked over at the now two soaking wet adults, Kita being the first to notice that the female's undergarments could be seen under her dress. Grabbing a towel, he went over and wrapped it around her body.

Y/n smiled at the male, holding onto the towel, "Thank you Kita." to which he nodded in response. 

Going through her bag, she took out some extra clothes that she thankfully brought with her, just in case something would happen to her dress.

"I'm going to go change my clothes" she told the boys before glancing around and noticed Osamu and Koji together. She smiled in approval and made her way to the changing room. 

"Why're you all red Atsumu?" Akagi questioned the blond. 

"It's none of your business..." Atsumu muttered, trying to calm down.

"Probably because he has a crush on Y/n again~" Hitoshi teased which made Atsumu's face go even more red.

"Would ya shut up!" he glared at his friend who only snickered. 

"Mommy look at the sandcastle me and 'Samu built!" Koji called out.

Looking around, he only saw the males and not the woman he loved so dearly. Turning his head, he went to the group of men.

"Where's my mommy?" he questions them.

"She ocean swallowed her" Atsumu joked which earned a good whack to the head by Aran.

"Stop messing with him." dark skinned male sighed out. He squatted down to look at the small boy who was trying not to cry, making him smile and rest his hand on his head. "She just went to go change her clothes since she got them wet." he explained.

The boy nodded, quickly wiping away any tears that were about to fall from his eyes.

"Why don't you show me your sandcastle?" Aran smiled, looking at the boy. His eyes gleamed and nodded in response.

"C'mon! 'Samu helped me make it really reeaally~ big!" Koji took Aran's hand and practically dragged the man to the sandcastle he and his uncle built. 

Aran chuckled, slightly bending down as he followed Koji since he was a literal giant compared to the tiny bean. 

Once Y/n came back, she was wearing a regular t-shirt and shorts. Standing with the men, she noticed Koji talking to Aran about his sandcastle. She smiled, watching the two from a distance. But it wasn't long until Koji noticed his mom had returned, making him break out into a grin and wave his hands over his head.

"Mom! Over here!" he called out.

Y/n chuckled softly and waved back, making her way over, Koji meeting her halfway. He tackled her into a hug, clinging onto her legs as he looked up with a dopey grin.

"I missed you!" he said. 

The h/c haired female chuckled, cupping his cheek with her hand while he nuzzled into it. 

"I was only gone for a little while silly." she smiled softly as he smiled.

"I know!" he chimed. "Come on! Look at the sandcastle that me and 'Samu built!" he exclaimed.

Y/n chuckled softly, following the small boy that lead her towards his castle.

"I'm coming I'm coming" she said. 

At some point, they all had to pack up their stuff as the sea slowly started to swallow the sun. With little daylight left, they all sat on the sand and listened to the small made up tune Y/n was playing on her ukulele that Koji had made her bring. Koji laid in her lap as he was trying to fight the grogginess that was getting to him. 

"Get some sleep rice ball." Y/n softly stated.

"Koji isn't...sleepy though..." he yawned in between his sentence making her softly chuckle.

"You have to go to daycare tomorrow though, we can't have you be tired during daycare." she stopped strumming the small stringed instrument and moved his soft hair away from his face.

"There's naptime.. mommy..." he mumbled, making Y/n smile.

Unbeknownst to the two, Atsumu stared at the endearing interaction the two were having. He stared at the woman with adoration and admiration, proud that she was able to make it so far as a single mom.

"Take a picture, it'll last longer" Suna told his friend. "I would know, because I have all of your and Osamu's fights in my phone."

Atsumu glared at his friend who quietly snickered, though he did have a good point. Quickly taking out his phone, he took a picture of a sleepy child with his mother holding him so dearly. Without wasting another second, he made it his lock screen. He smiled, looking at the picture he had taken.

"That's pretty creepy" Osamu chimed, looking at his brother's new lock screen.

"Shut it!" Atsumu hissed. Osamu only smiled in amusement before continuing his conversation with Suna. 

With the sun now fully gone, the stars and moon started taking their place in the dark empty sky. Y/n held Koji in her arms while she set her ukulele down next to her bag. Leaving her bag and instrument behind for the moment, she went to go put Koji down in the car. 

Osamu nudged his brother, making Atsumu look at him.

"Go help her." he ordered. 

"Yeah yeah." Atsumu grabbed the female's belongings before heading over to the car. He watched as she buckled Koji up. Going on the other side, he opened the door and set her bag and instrument on the passenger seats.

"Oh, thank you." Y/n smiled at the blond who smiled back.

"No problem." the two closed the door and noticed Osamu walking over to them.

The grey haired male tossed the key to Atsumu who caught it with ease. 

"I'm hitching a ride with Suna and Hitoshi" he explained to the two. Walking over to his twin, he put a hand on his shoulder, a stern look on his face. "Don't screw this up for yourself" he adviced.

"I won't!" he exclaimed, becoming annoyed with his brother.

"Sure." sarcasm seeping from his voice. Going over to the female, he gave her a small hug before ruffling her hair.

"Thanks for coming." he smiled at the female who gave one back.

"Thanks for inviting us. Koji really enjoyed it." she replied.

He nodded and started to make his way to Suna's car. "I'll see you at home 'Tsumu!" he waved goodbye to them before going in the car. 

"Lets get going as well" Atsumu stated, making the female nod in response.

The two adults going in the car, Atsumu started the engine as they drove off and headed to the female's apartment. The drive was quiet between the two adults. Atsumu keeping his eyes up front while Y/n stared out the window. 

Y/n pursed her lips, wondering to ask the male a question or not. Biting the inside of her cheek, she hesitantly decided to ask, hoping to not regret her asking.

"Um..." she cursed at herself with starting her question off with 'Um'.

"Yeah?" Atsumu glanced over at the female who kept her eyes glued to the window.

She shifted in her position, her whole body now facing the front. She fiddled with her fingers, her hands becoming clammy.

"Why..." she bit her tongue, feeling her heart rate start to increase. "Why did you leave...?" she questioned, her voice becoming soft and quiet. She glanced at the blond who kept his eyes on the road. Quickly averting her gaze away from him, she let out a quiet shaky breath.

Atsumu tightened his grip on the stirring wheel, his jaw slightly clenching at hearing her question. 

"It's fine if you don't want to answer." she quickly added.

"No!" he cleared his voice, glancing at the rearview mirror to make sure he didn't wake Koji. "No, it's fine" his voice was more soft.

Both of their stomachs were churning, awaiting for his answer. Atsumu opened his mouth, but quickly closed it.

What was he going to say? Trying to think of an answer while driving had somehow made it more difficult for him. He repositioned his hands on the steering wheel, his eyes glued to what was in front of him.

"I..." he furrowed his brows, trying to think of something. "I felt that.. I felt that it was the best...For both you and me." he answered.

"Right." Y/n responded, already feeling bitter about his response.

Atsumu pursed his lips, knowing that the female wasn't satisfied with his answer, so he continued.

"I know I'm an asshole." he started. "But...I wanted to become a pro volleyball player, and you just wanted to stay in Hyogo." he explained. "I had a hard time with this decision as well." he spoke slowly, making sure he chose the right words and understood what he was saying.

"You meant the world to me Y/n. But at that moment, being the prick that I am, I decided to choose to continue down the path of my career, rather than being with the girl that I loved." he glanced at the woman that sat next to him to see her reaction.

It was quiet for a moment until she let out a small sigh.

"Understandable..." she went back to looking out the window as they passed by everything. "You loved volleyball more than anything." a small smile made it's way to her lips, reminiscing their high school days where Atsumu would bother her to toss to him so he could perfect his sets. 

"You could've at least told me why you were breaking up with me." she said.

"If I did, I think you would've buried me six feet under." the two chuckled softly at his remark.

"Probably." she replied. "But..." she watched as a car passed by them and tightly held onto her hands. "I think..." she let out a shaky breath, trying to calm herself down. "I think I would've told you I was pregnant with him, as a way to try and make you stay." 

A/N : I'm sorry for taking so long to update even though I just said I was getting off of my hiatus. School started for me this month so things have been a bit hectic. But also I've been working on a personal story of mine that maybe you guys are interested in and not just my x readers?

Let me know in the comments if you guys are interested in the story I'm making! Also, as a way to apologize for making you guys wait, I decided to make five chapters instead of just one, including this one. I hope you guys enjoy and welcome new readers!

(Also I was planning on surprising you guys with a five chapter update but I literally have no idea what to do for chapter 18 so just take a double update OTL I'm sorry I took so long)