Obvious to everyone one else except the person (or rather, the two people) in question I would say.
Our FMC is running the standard fervent denial of having the MMC falling in love with her due to following the 'route' of the story but things are already altering from what she remembered so now she's more susceptible to the idea. Albeit only somewhat.
I'm thinking this would be hilarious if she got the revelation via the style of "I failed to divorce my husband" kind. But this time with the roles reversed and adjusted.
a yes the famous "see an illusion of what your truly want to advance the plot" truly the best and an organic way to right a story and move the plot, not boring and overused
I mean I am reading a romance isekai webtoon, so I can t really complain that much about it being boring overuse trope because sadly at this point this is the main feature of the genre of stories...
Wait, we're claiming that he was doing all these cringe semi-stalkerish things (be it getting up in a fuss over whether she was interested in a boyfriend, or taking up kinda sketchy tactics to prevent her from leaving, whatever) without realizing that he's got a crush?
...Honestly author-nim, that doesn't make me think he's "pure", that makes me think he's ducking terrifying.