Is this Shounen ai? Sorry for asking but i'm curious

I would say yes, but it's just brotherly love.. Maybe idk but maybe it's more than brotherly love for the younger brother ╮(￣▽￣)╭

Ohh Thank u and i already finished it and it's so Painful T_T

i would say yes (in a really messed up yandere way) cause if you look at the earlier chapters, before he unchained his psycho self, when ever he was close to his brother Yoseob focus a lot on his lip or other parts of his body.

Anther example is when Yura couldnt figure out why Yoseob would be jealous of her
though the author seem to drop that angle to make way for his worsening mental health