I do feel like even in smut manhwa or Manga, sex scenes are very unrealistic, straight or not. Look how in smut manhwa where a guy has a big dick and the girl just moan loudly on how it felt so good because of his big ass dick but realistically it'll be painful as hell. So yes, even in BL manhwa it's rare to find authors who is good at making sex scenes
They’re always complaining about how much their backs hurt after the fact, yet immediately after they’re walking or doing some other physical activity like it’s nothing.
Like how?
I’ve thrown out my back and am pretty useless for a few days and in general sometimes get lower back pain that makes moving around annoying, so I’ve always wondered how these characters are like “im dying” then next scene they’re going about their daily lives like nothing hurts.

-When someone grabs a ding dong, 90% chance it is already hard. Seme always walk with a hard on, no matter the place, day, or fatigue, they are always ready
-semes have a hard-on the size of a horse, it goes from the an*s to the mouth without any biological problem for the uke
-bulge. Very absolutely anatomically normal
-Sometimes seme just have to thrust in to be good at sex. Because.
-when the author want to show that the uke has no sexual experience, the uke always give a bad blowjob. But somehow the seme manages to cum. Semes are such nice guys.
-“it’s so big, it will never fit!” All. The. Time.