I have two theories:
1 the girl who did the whole matchmaking thing is in love with another girl, but she is not ready to admit it, or was told that's bad and that's why she's not going back to Seoul, because that's the problem she has, and she saw Haebom with a man so she panicked because "wasn't that supposed to be bad" so she decided to do the "correct" thing for him
2: she's actually just homophobic lol
1 the girl who did the whole matchmaking thing is in love with another girl, but she is not ready to admit it, or was told that's bad and that's why she's not going back to Seoul, because that's the problem she has, and she saw Haebom with a man so she panicked because "wasn't that supposed to be bad" so she decided to do the "correct" thing for him
2: she's actually just homophobic lol
