Seems like my reply got cut somehow. Anyways what I'm saying here is that each of them was having a making decision time and they hadn't made anything official yet. Noeul might not have been good from A to Z but at that time he was trying to get over his one sided crush, I understand that tho I'm not on his side when he made out with Yeoreum (i blame the author for making things easy for yeoreum), he had not accepted Luna's love words and Luna also hadn't officially confessed. Again, they did not belong with each other so calling out Noeul for "cheating" is a bit much, tho i see how uncomfortable you are with those actions.

I don't understand people who’s saying that Noel should end up with luna???! Noel literally cheated (even though they’re not officiall but every time he invites luna he cheat on him either by thinking about Y or sleeping with him yet he denied that saying he is only thinking about luna when he is with him!). I think Noel did Luna dirty like Y did to him, so both N and Y deserve each other! While Luna need a loyal better partner!