hi anon that's a very open-ended question and this got long so if there's one thing to take away from this just read the next paragraph. i'll start off by saying these are my opinions so i'm going to cut out all the "i think/feel/believe", "imo", "to me" filler lol.

their dynamic is a lot more complex than the "jay is whipped and jungwon is a playful kitty" narrative that people can reduce them to. yes they're in love with each other but do they know jay is always holding himself back with jungwon and only goes as far as jungwon is comfortable with. do they know jungwon is always repressing his feelings because of the high expectations he thinks people have of him so he can't show his affection for jay normally.

i tweeted something a while back that explains where i'm coming from so let me put it here too: "thinking about yangjeng's relationship progression from i-land to debut to that 1 year jw was okay with jy being clingy to telling him to back off (came to me in a vision) to their present day mutual obsession and play fighting bc jw can't take back what he said years ago".

jay has alwaysss been in love with jungwon it's insane, whereas jungwon is the real bottleneck in their relationship progressing any further. which is funny when you think about how jungwon is the one who's more obsessed between the two of them. his constant need to bring up jay at the most random times and enjoyment of tormenting and teasing him are manifestations of him being unable to normally show his affection for jay, and the more he represses his feelings the more he keeps doing it this way lol.

it's cute because jay accepts anything he can get from jungwon and his favouritism towards him in particular is very obvious... jay enjoys all the attention from jungwon even if he pretends otherwise, but i don't think he realises that jungwon acts this way because he loves him A Lot. who up thinking about that one weverse comment he made where he said this is the Worst choice he's ever had to make re: OP asking whether he'd rather have ni-ki or jungwon as a hyung like you have got to be kidding me. jungwon would treat you So Well if he were your hyung.

again, jungwon can't tell jay how he feels outright because he has his ridiculous harsh self-imposed rules and he's an avoidant, but jay won't take any steps towards jungwon either because he's afraid of scaring him off (and he already got scolded by jungwon once for being so clingy when they were younger (ok this one's a headcanon but allow it)) and he's happy with whatever he can get from jungwon. at least that's what he tells himself. he's dying on the inside actually. so they're stuck in this beautiful cycle of miscommunication and misunderstandings. MY FAVOURITE!

i'm not sure that this fully encapsulates everything i feel, but if you scroll through my alterspring i have a bunch of asks on jaywon answered already. feel free to agree/disagree and lmk what you think...