The only explanation that makes sense to me is that she felt different from her friends because she didn't have a normal relationship with her parents, and the result of that was loneliness. Given that they are "different," maybe she doesn't want them to feel lonely in the end. However, it's none of her business what two grown adults are doing in a consensual relationship, so I'm still confused.
Babe, what are you confused about? Even she herself knows that she's made a mistake. She's a kid and she did something wrong with her kiddie brain. Nobody's hurt and she apologized.
Ho and Beom are two grown ass men with lots of experience, a college student throwing a tantrum won't do anything to their relationship.
I don't understand her reasoning like what does that have to do with two homosexuals kissing