I know this comment is a year old, but I couldn't help but to comment.
I don't see anything wrong with it because they're the same sex and it's not an omegaverse, so they can't have children. Besides, there's a difference between siblings if you didn't grow up with them.
I'm not blood related to my brother (both adopted) but since I grew up with him, the thought of anything sexual to do with him makes me ill. If you didn't grow up with your blood sibling, it's like meeting a stranger. No different from falling in love with some person you met in school or the supermarket or something.
Hmm, fair enough
This is so fucking weird reading a bl about actual blood-related brothers... I cringed so hard at the smut scenes, and the fact that he called Miharu Brother constantly during sex made me so uncomfortable!! like imagine if you did stuff with your blood-related sister and your parents didn't know?? Just thinking about that makes me grimace (⊙…⊙ )
Well, incest is fucked up but at least this is fiction.. step brothers I would've been more comfortable with. Oh well.
On to more important matters, R.I.P. pie :( ypu never got to see the inside of Natsu's stomach </3