The problem is that in the last chapter, she confirms she met with a man at that hotel to erase those sexual urges! And the MC says he doesn't care because he has him! He's been left looking like a cuckold! Before, I thought it was just going to be pure NTR bait since this was supposed to be a romantic comedy, but now I don't know what to think, since the author hasn't given us any hints or clues about Luna's secrets. Anything could have happened at that hotel, but now I'm about 60% inclined to think she slept with someone else to erase her sexual urges for the MC. That's why, when she was masturbating in previous chapters, she's looking for someone on a dating app.
If this is true, what a huge disappointment it would be. The author is playing with fire. On their account, in their last tweet promoting the last chapter, they limited the comments, which means the hate is coming. By the way, in the previous tweet promoting chapter 25, the comments are open, and they're really throwing a lot of hate at them.