It’s  hard to say why they are best friends in just a couple of words and it’s even harder to explain why they are just that and nothing more and never will be, because they are so close that people assume stuff and people always think they know better but they don’t.
Junhong is really just Jongup’s friend and it’s the same the other way around but neither of them would ever deny that they love each other, a lot!
They love each other more than anyone else but it’s just not that kind of love, with butterflies and awkward giggles, flushed cheeks and sweaty palms but a different type with mutual understanding without the need for words and a calm settled in their bellies and lots of laughter and sometimes shared tears.
Sometimes the both of them agree that their love is the most beautiful kind of love because it’s not demanding, it’s just there and it’s theirs and they are best friends and sometimes the feeling is so strong that it feels like they own the world as long as they are together.
 

They are best friends because they don’t mind doing things for each other even if they don’t feel like doing them at all.
They may not like doing them, may rather want to watch a movie or take a nap but they still do whatever the other asks them to because they do them for each other and when it’s for their best friend it’s just not as annoying to do as it would be to do for anyone else.

They are best friends because when they confess to each other about things that are on their minds, things bothering them, things that can’t be dealt with all alone but can’t be shared with anyone else, they both listen as the other talks.
They don’t judge or laugh or give useless advices, they just listen and nod and understand even if they don’t understand at all but what they understand is that it’s important for the other and with that it becomes important to them as well.  

They are best friends because no one else ever gets an insight to their silent conversations, those conversation that are solely held with their eyes and the up and down curves of their lips.
They understand, even when nobody else does, they just know what is on the other’s mind, whether it is a pun on words, a joke crossing their minds, an aversive thought or a simple agreement, even the flash of an deeply rooted emotion, they just know and they understand as easily as breathing.

They are best friends because a simple seeking look or a short call in the middle of the night is enough to make either one of them willingly go through hell end back, just to get to the other when they are in need of an open ear or a shoulder to lean on.
There aren’t even questions of –why- or –when- lingering on the tip of their tongues, merely the promise of –I’ll be right there- making it pass their lips, always.

They are best friends because they like the same things, like the same music and the feeling that rushes through their limbs when they are dancing and even the things they don’t share to enjoy they still enjoy together, like skateboarding and singing, they do them together because one of them likes them and so the other kind of automatically does too.

They are best friends because they never argue, they disagree from time to time and may stop talking for a day or two but it’s never longer because after all they can always accept the other’s opinion and it’s better than always agreeing with each other because they get to discuss about what they disagree on for hours on end and when they are done they happily agree to disagree and change the topic to something they both chime with.

They are best friends because they can hug and cuddle and it’s never awkward to do because it’s them and that’s why it’s natural and calming.
It’s settling to feel each other’s embrace and it makes them feel like kings and gives them strength and sometimes it’s just right to do, to show how much they mean to each other.
 

They are best friends because at parties, when there’s alcohol and girls and sometimes boys involved, they keep an eye on each other, always attentive to their surroundings, always watching who comes and goes, who’s friend or foe and even though they don’t interfere too much and they get each other drinks and sing random songs off tune together when the liquor flows their veins, they always make sure the other doesn’t cross a line they might regret later.

They are best friends because even after they spend a long time apart and also in case they ever get separated, they just know they will always have a place or rather a person to come back to.
Even after weeks of not being able to see each other or talk properly, the moment the two of them get back together it’s just as perfect as it has always been.

They are best friends because there is nothing, not even one single thing that’s really embarrassing to happen, to do or admit to one another.
Sometimes surely, there are things that make one of them blush or laugh awkwardly while rubbing their necks but it never really matters because the other never judges, never laughs too long, though probably louder than anyone else at first but that’s just for a moment until they both laugh together.

They are best friends because they always go to pick each other up when one of them needs a lift, well…their hyungs do but they talk them into it, Junhong convincing his neighbor Youngjae with his big doe eyes, Jongup convincing his cousin Daehyun with his pouty lips and sometimes they don’t even need to ask when their puppy eyes appear and people just know what they want and comply without arguing.

They are best friends because they can be bold with each other and they always are.
There’s no one else allowed to say the things the two of them say to each other, stating how they think the other’s hair is ugly or the new pants are too tight or the new tech-toy they got is a piece of crap cause there’s way better choices out there. They can say all those things without beating around the bush because though it stings a little, it’s an opinion they accept and respect no matter how bluntly uttered.

They are best friends because they can toss cuss words at each other’s face and call each other names and it’s never meant to hurt, it’s just because they can and nobody gets it when Junhong says “” and Jongup replies “” and they burst out laughing and holding their bellies because it’s nothing different from calling each other sweet, corny nicknames but peoples jaws drop around them and that fact is hilarious.
 

They are best friends because they know each other’s favorite food, song, book… everything by heart and if they actually don’t remember or if they are unsure about it their first guess will always get closest to the real thing because it’s easy to tell when they spend so much time together.

They are best friends because they can pretend not to be, because they can fake flirt and put up an act that is so convincing that sometimes it gets the both of them as equally confused as their surroundings.  It’s an easy thing to do because they know each other too well and when they look at each other with that little spark in their eyes and the glint of admiration; it looks so real because it is after all. They do like to be around each other more than not and they can’t imagine being without the other ever and it’s just a strong bond that no one understands except Junhong and Jongup themselves.

They are best friends because there’s just no one like them, there’s only Junhong and Jongup, Jongup and Junhong and that won’t change, just maybe a little but never vanish completely, for what might be somewhere close to forever.

(Note: Donno where this came from...I probably forgot some reasons but I can't think of more right now...I wanted to add moments to every reason but I feel it would be too much right now ^^; Hope you enjoyed)