Time skipped:-

"You're gonna go back, right hyungie?" Jungkook tried his best not to sound sad but failed as Jin's brows tightened a little with worry as he unbuckled the seatbelt of the latter. So he added, "I'm fine, don't worry."

Jin lifted his body up carefully and made his nine months pregnant boyfriend stand on his feet. Wrapping a hand around his waist from back, he led themselves towards the house. 

"Hyungie will try to come back early." Jin spoke while wiping his sweaty forehead off with the palm. After opening the door, he faced the younger to kiss his nose and lips. 

"The results for the tests we did today would turn out okay, right hyungie?" Jungkook questioned, caressing Jin's arm softly. "Seokkie's fine, no?"

"Yes sweetie, he's all healthy." Jin held his hand and walked him to the couch. Jungkook sat there and Jin pecked his lips once again before bidding goodbye. 

............................

Jin took a deep breath before entering the hospital building. He didn't smiled at the girl in reception area as usual nor his fellow colleagues. Instead, he wore an unreadable expression on his face all the way towards his cabin. 

He secretly glanced around him twice before entering it and closed the door. Then he went over to his work desk and pulled out a small blood tube from the locker. 

Jin slipped it into his lab coat before wearing it and made his way out of the cabin. He walked through corridors and travelled three more floors up to reach the destination on his mind, the 'Genetic Laboratory'. 

He closed his eyes tightly and opened them back before entering the room where he saw a several lab assistants working by machines. He went over to a young boy, who was sitting at a far end and tapped his shoulder. 

"Oh, Doctor Seokjin!" the boy quickly stood up and bowed. "Can I help you, sir?"

"Yes Eion, I need you to run an NIPP test, right now." Jin said in a low voice as he pulled out the blood sample. 

"It'll take at least three days to receive the result Dr.Seokjin, is it okay?" Eion asked and Jin pinched his nose bridge impatiently. 

"Okay," he agreed with annoyance. "Promise you'll keep this as a secret, Eion?" 

The boy looked confused for a moment. "But you always brings..."

"...This one should remain as secret, understood?" Jin barged in and Eion nodded right away. "I'll pay you extra if you do this right."

"No need sir, I'm more than happy to help you." Eion smiled as he took the blood sample in his hand. "So where's the other tube?"

Jin bent down a little and whispered, "Me"

Eion's eyes went wide as golf balls as he stared back at the tall doctor. 

"B-but? A-Aren't you..?"

"Yes, I'm not married but that's none of your business. Just do what I ordered Eion, please.."

"Consider it's done, Dr.Seokjin."

(*NIPP- Noninvasive Prenatal DNA Testing)

..........................

Jin knew it was wrong. 

Wrong to steal a blood sample of Jungkook without his concern. And running a test on it. 

But why so sudden? What exactly happened?

Because...

Because Jin decided it's enough of pretending. Pretending that he'd accepted Seok-hyun as Taehyung's baby...When he knew the truth all this time. Or more accurately, what happened that night. 

Jin wanted to make sure of his suspicion and this's the only way he could do it. He had already made up his mind to spill everything to his beloved boyfriend. He's tired of lying. He wanted Jungkook to know that their Soekkie was born of his own blood.

Jin wasn't sure how Jungkook would react to the shocking news but he knew it would be positive. 'Cause Jungkook had already proved he wanted to be only with him. 

But unfortunately..... he was wrong. Like, super wrong.

He should've think twice.

.......................

Three days later, Eion brought the results of the test to Jin's cabin and as he expected, it matched. 

Jin was indeed the biological father of Jungkook's baby and tears of happiness welled up in his eyes immediately. He thought about sharing the news with his best friend first. 

But Ken's reaction for it was totally unexpectable. 

"WHAT?" Ken roared, slamming his hand on the desk. "H-How can you even say it without being ashamed, Jin?"

Jin's face darkened as he stared at his friend. "W-What do you mean?"

Ken dropped onto his chair with so much anger in his eyes. "You're such a beast Jin. How come you never tell me about this in the first place? Th-That you had sex with Jungkook on... on your e-engagement party? Are you fucking kidding me Seokjin? Is that poor boy's life is a game to you?"

"I-I.." Jin stuttered uneasily as he spotted Ken's reddened eyes. 

"You're worse than Taehyung Jin. So much worse than that. You ruined the innocence of that pure boy and now talking like it's the most normal thing in the world. I never knew you could be that heartless Seokjin." 

Jin's vision started to blur slowly as tears started to pour down his eyes. It became harder when the truth started to dawn on him. He felt helpless, insecure and angry at the same time. 

"I-I didn't think o-of that K-Kennie...I-I'm sorry. I w-was just too much happy to know S-Seokkie's m-mine. I was b-blinded.."

"The baby doesn't deserve that name Jin." Ken pointed at the door and said, "Get out!"

"I-I'm sorry, I-I was drunk.." 

"Is that even an excuse Jin?" Ken retorted. "You nearly destroyed Kookie's life!?"

"I-I should g-go Kennie, th-thank you!" Jin stood up from the chair with wobbly legs, hugging the plastic file which held the NIPP reports, closer to his chest. He didn't even noticed he was crying bitterly. 

Ken's expression softened a little as he saw his best friend's pathetic state. He also got up from the chair and walked over to Jin before holding his shoulders. 

"Look Jin," he said after sighing heavily. "You don't have to be faithful for Kookie all the time. Just this one last time be dishonest and keep this report away from his eyes. He won't be able to bear it once he get to know it Jin, trust me."

Jin sniffed his nose, handing his head low and nodded slightly. "O-Okay."

"Okay then," Ken sighed again. "You should take some rest at home. I'll look after your shift."

Jin just nodded and walked out of the cabin with a heavy heart.

At least he himself knew the baby's not Taehyung's but his. 

Jin burst into another set of tears and sobs as soon as he locked himself in his car. He banged his head on the driving seat and wept bitterly. 

'I'm a sinner' He mumbled it thousand times through the cries. 

.............................

Jin stopped his car in front of their home, not having any thoughts of pulling into the driveway. He turned his gaze over to the small house which had given him so much happiness and then looked at the reports file on the passenger seat. It didn't took much longer for the waterworks to start. 

He slid his palm smoothly over it as a sob escaped his mouth. 

"I wish I could turn back time." he mumbled to himself. "Then I could've given him a baby, the way he want. It didn't have to be from drunken sex. I-I'm so stupid."

He sighed heavily and wiped away the tears with quick moves. He knew Jungkook was asleep at this hour of the day so he didn't bothered washing off his face. 

Jin took the file in his hand securely and left the car right there in front of the gate. Then, in slow steps he walked over to the house and unlocked the door only to gasp in shock, seeing the younger on the couch smiling at him. But soon the beautiful beam dropped down from the latter's face as soon as he spotted the elder's face. 

"H-Hyungie?" He carefully got up and started moving towards Jin with a worried look. "A-are you alright?"

Jin tried to look everywhere but his eyes as he replied, "Y-yes.."

"No, you're not?" Jungkook touched Jin's wet cheeks with shivering fingers. "H-Hyungie did manager-nim scold you?" 

Jungkook was so surprised to see Jin crying 'cause he rarely became emotional. As far as he knew the only reason which could pull out Jin's tears is, he himself. And Jungkook was sure he had done nothing wrong this time. 

"I-I'm just tired sweetie.." Jin hiccup, trying to swallow his sobs. "Why a-are you awake?"

"I was just scrolling through some pictures of us from Suncheon but that doesn't matter now. Hyungie please tell me, what's wrong? Is it about me?"

Jin nodded then immediately shook his head. 

"It's me?" Jungkook looked so sad as he hugged the elder with his chubby hands. "I-I'm so sorry hyungie. I didn't do anything wrong on purpose."

"I-It's not you my babe..." Jin crocked out but even before he knew it, Jungkook's hand hit the report file and it slipped out from his fingers making the pages flew out of it.

"Oh s-sorry hyungie...I'll get that." Jungkook told trying to catch the page which landed on the nearby cabinet. 

"No, Jungkook NO!!" Jin shrieked but the younger was already reading it.

"Wh-Why is my name printed on this DNA test report?" Jungkook frowned as he kept on reading it furtherer. Jin stood there helpless, not trying to snatch it away from Jungkook's hand just in case of something bad happen.

"A-And my Seokie's? Y-You didn't say anything about us running a DNA t- Oh..Oh n-no..." Jungkook felt like he was gonna faint and Jin immediately caught him arms. 

"P-Please babe, don't stress yourself." Jin mumbled in pain as he made him sit on a sofa. Ignoring the dizziness, Jungkook once again started to continue reading. 

"Th-The alleged father c-cannot be excluded as the b-biological f-father o-of the tested child. B-Based on the analysis....W-Wait a-and....y-you...how? Wh-When did?" 

Jin knelt down in front of his and with teary eyes as he said, "Yes m-my babe, Seokkie is ours. I'm his Appa.."

"N-No..." Jungkook cried as tears started to flow down from his eyes. "How's that e-even possible hyung?"

"I-I'll tell you my sweetie but a-aren't you happy? You said you don't mind being pregnant for m-me the other day, r-right?"

"No I don't!?" Jungkook shouted. "Not in this way hyung. W-When did we even... I-I don't remember sleeping with you t-ten months ago?"

"I-It was..." Jin stopped for a while, staring into Jungkook's hurtful eyes and gulped. "It happened the night of my engagement party. We b-both were drunk and I-"

Jin couldn't finish the sentence as a harsh slap landed on his cheek. 

(A/N: Any questions? I kinda rushed through this chapter btw, sorry..)

*The NIPP test can only be done during the third month of pregnancy, according  to the article I read. But this's just a story so don't think of it much. Enjoy the week!