It was my personal opinion from her crazy character. Maybe because at first she just want jeong won, he rejects her and all engagement talk never did, she give up so she want what sera has it is jae eon cause she want to make her feel bad too by taking everything she has and be the fl, her engagement talk was a lie, but at least shin sera's engagement really happen but currently sera personality is changing, the factor why she not easily give up on jeong won, she think sera want him too, what is hers and be her rival
in the og timeline, the interaction between jae eon and og fl is only him going along with the og fl, but not ever really loving her, maybe just caring enough about her to destroy the villain character. I feel that's how he ended up with og fl. Now in this new timeline, sera changed Jae eon. She is feisty, lively, interesting. He is attracted to sera and now has motivation to not end up with the fl.
thankk youu new grp for translating !!!
wasnt Seonkyung the og fl who ends up with Jae eon in the og storyline ? why she tryin too hard to be with Jeong won? Not like i care tho but just wanna know