It's not complicated

Next morning, Jungkook prepared breakfast. He woke both Namjoon and Jin up. After 3 days, Jin came out of his room. After seeing Jin puffed eyes, Namjoon joked," Jin, you really looked like chimpanzee."
Jungkook slapped Namjoon," Don't tease him."

Namjoon," My dear Kookie how could you hit me for him?.. Oh! God My Kookie beat me even though I had raised him. Did I raised him for this day?"
Jungkook putting bread in Namjoon's mouth," What a drama queen."
Jin smiled. After seeing him smile, both gave a sigh relief.

Jin," What?..Did I make you that worried?"
Jungkook and Namjoon at once," Yes."
Jin,"I'm sorry to make you worried."
Jungkook," Nah..You.."
Namjoon interrupted," Then tell us the reason of making us worry?"
Jungkook gave no sign to Namjoon but he added," What?.. I don't want to be his babysitter again?"
Jin sigh," Actually I'm.." paused.

Jungkook," If you don't want then..."
Jin added," Actually my mother used to have two sons."
Namjoon," used to.."
Even though Jungkook already knew this story still he want to listen it from Jin so he just listened.

Jin," My elder brother died."
Namjoon," Sorry for that."
Jin," Because of me."
Both Jungkook and Namjoon got shocked from this Jin sudden confession.

Jin," When I was little, I used to live with my mom and my Hyung.."
Namjoon interrupted, "And Dad..?"
Jungkook irritatingly," Stop interrupting, Hyung."
Namjoon," Sorry..Sorry."
Jin," I don't know where he was.. My mother never tell us about him. But suddenly he returned. He used to beat my mother.."
Namjoon," Didn't your mother ask for help to police?"
Jungkook gave irritating look to Namjoon.

Namjoon," Okay..I will shut up."
Jin," I don't know.. She never tell police..When I was eleven I became aware of myself.. "
Namjoon," Aware..Sorry Sorry.. I think I should put this bread in my mouth." Putting bread in his mouth to shut himself up.

Jin," That I like boys. I told it to my hyung but I could not tell my mother. I had a crush on one of neighbour."
Clenching his hand," I don't know why I did that..I don't know why I confessed to him..That person told everyone that Min Johan's son is gay.."
Namjoon," Who is this Min Johan?"
Jin," My real father..bursting to tears,
" My brother told me he wanted to bath first so he went to bath house and asked me to stay at home until he came back..I waited for him. My mom came home but he did not...When I reached..." Trembling, " there was blood..lots of blood covering his body.."
Jungkook hugged Jin..

Jin still trembling," And then my father started to beat me up...I got hurt but he did not stop..He tell me it was because of me he died..He just beat...."
Jungkook," Enough Jin..It's okay that person is not here..It's okay.''

After some assurance Jungkook left Jin in his room. He did not let go of Jin's side. Careressing Jin's hair,he asked sleepy Jin," Jin, What was your elder brother's name?"
Sleepy Jin whispering," Min Suga."
Jungkook got  puzzled from Jin's answer. Jin had not sleep for almost 3 days, so he easily fell asleep. Jin phone was beside his bed. Thinking it may disturb him, Jungkook took it with him.

Jungkook came out of Jin's room. Namjoon still had question in his mind.
Jungkook looking at curious Namjoon," Hyung Can you do me a favour?"
Namjoon," Ask anything."
Jungkook," I need to know every detail of this Min Johan and Jin's  dead brother."
Namjoon quickly respond," I'm on it."

After Namjoon left, Jungkook accidently click on Jin's phone. It was switched off. Jungkook start it but he had to enter the pin. Jungkook thought may be Jin's birthday but it did not open.
Jungkook," Could it be.."
Entered the pin and it opened. That Pin was Jin's brother death year. During looking at the information given by Tae, Jungkook saw it.
There was lots of calls for Jin and mostly it was unknown number.
Jungkook did not think that much at first.

But suddenly he got called by an unknown number. Jungkook picked it up," Hello!.."
Unknown number loudly," You really had guts to switch off ..huh.."
Jungkook pannicking," Who is it?"
Unknown number," It's not Jin's voice...Could it be Mr. Jungkook?"

Jungkook was quite shocked at first but he remembered Tae's warning so he calmly answered," Could it be Mr. MIN JOHAN?"
Unknown number," So you knew about me..Huh..What other things that bixxh told you?"
Jungkook angrily," That person is my husband."

Unknown number," Oh..So there is another shameless person..huh..
Jungkook," What do you want?"
Unknown number," I want him to taste suffering.. I want him to taste every humiliation.."
Jungkook," Even though he is your son,..how.."
Unknown number interrupted," That person is not my son. That person kill my son. How can he be happy after killing my son..I'm not going to let him happy."
Jungkook grinning, " Then lets talk face to face. Do you dare?"
Unknown number," I like challenge."
Phone cut off.
Jungkook immediately send that number to Namjoon for investigation.
Jungkook had a hunch he had already contact Jin by judging the frightened Jin.

After few days, Jin behave normal as usual. Jungkook did not tell Jin about the call but informed Yoongi, Namjoon, J-Hope,Jimin and even Tae about it. Despite he didnot want help from Tae, but Tae knew lots of information which can be favour for Jin. After few days, Jin's parents returned. Jin's mom was only person who knew every secret. So Jungkook alongside Jin made arrangement of dinner with Jin's parents. After greetings, they chatted for long. After meeting with his parents, Jin was very happy and had a long talk with his father.

At the same time, Jungkook excused with Jin's mom.
Jin's mom," My son is not bothering you right, Jungkookie."
Jungkook jokingly," Of course..He bothered me too much."
Jin's mom," Really?..He is same like me. I also love to bother his father."
They both laughed.

Jungkook hesitatingly," Well.. These days I had really make lots of fans.:
Jin's mom," WOW..Really..I am also one of your Fan."
Jungkook," Really?..Actually recently I got lots of messages from my fan at my websites..There is one who usually compliment me and I like his compliments..Umm..What was his user name..Let me think..Oh! Yeah.. MIN JOHAN."

Jungkook indirectly tell about that person because after seeing Jin, he felt Jin's mom also wouldn't had any good memories with him. And he was correct Jin's mom face colored suddenly changed. Her hands were trembling. Jungkook knew it was rude but still he asked," I know it's rude and maybe you don't want to tell but I knew Jin's father is Min Johan?"
Jin's mom," How did you...?..And why you want to know?.. After all these years that person is nothing to me.."

Jungkook," That person is bothering Jin."
Jin's mom," What?"
Jungkook told everything including Tae and Jin recent condition.
Jin's mom frightened and teary," How can he...Oh! My Jin.."
Namjoon suddenly called Jungkook.

Jungkook," Hyung..I am.."
Namjoon," Just listen quickly. Jin is not Min Johan's son."
Jungkook," What?"
Namjoon," Min Johan had left Jin's mom with only one son. But after two years Jin was born and you know what at that time Min Johan was not at home."
Jungkook," Huh?.. How can it be possible?"
Namjoon," Exactly. Jin's mom had cheated on Min Johan and as a result Jin was born."
Jungkook," What was the name of elder son?"
Namjoon," Umm..Min Suga."
Jungkook,"Hyung, I will talk to you later."

Jungkook looking at Jin's mom," Who is the real father of Jin?"
Jin's mom," Huh?"
Jungkook," Jin is not Min Johan's son, right?"

Jin's Dad suddenly replied," I'm Jin's real father."