the other thing is you can also make it sensual and high tension without ANY nsfw scenes at all, but they didnt do that either. a lot of the appeal of the whole vampire genre is the forbidden element of falling into addiction, or the line between civility and gluttony (most apt analogy i can think of is how people like to use pomegranates cannibalism as a metaphor for love)
seeing as we're getting introduced to probably a new conflict, im assuming this manhwa is a going to have an actual plot and a bit of worldbuilding, not saying that you can't fit smut into that, but i can personally see why the author would choose to keep this story / season r15. ╮(￣▽￣)╭
Why even making this story r15 why cater this story with scrumptious potential to teenagers (who btw read smut too and would appreciate a few nsfw scenes) if you can cater it to adults and really bring the best out of the intimate scenes. Not saying if should be a buttfuck-every-other-chapter story but this chapter with the first feeding scene had so much potential but because it's r15 it was pretty bland and anticlimactic. No hate srsl, I just don't understand that decision