How comes it is called cheating when they're not officially together?
Him inviting him means giving him hope and sleeping at the same time the same night with other? I don’t know what you call that but for me he’s cheating and playing with him
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 just feel he used him and he himself said that he’s acting like Y
I see where you're coming from. But first of all, he and Yeoreum was still fbuddies until the broke it up. Secondly, him inviting Luna over was to give both Luna and himself hope, not just Luna, and Yeoreum was the one screwed him over by coming uninvited. Third, Noeul and Luna hadn't been official, and Luna said it himself that he wanted to be in the position that he could be angry so up until the point which Luna and Noeul officially dated each other, Noeul could still consider another guy. Cheating means that you betray the one you're dating/married to (morally/legally), not the one you're about to (slightly morally). We don't ban people from seeking others while they're about to having a relationship with someone, but we don't promote and even judge (in mind) that action so in the end, Noeul did "cross the line" (moral problem), he did not "cheat" (moral and legal problem).
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!