
Well I seen then raws long ago, but the other day finally used then camera text translation.
I feel unsatisfied with the ending and disappointed with the uncle. ( ̄へ ̄)

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The girl comes back home and talks to her friend that alrdy knows she is in love with her dad. So then she goes to his apartment and enters.
That's it, that's the last page. They don't show the progress after she comes back.
And he does ends up sleeping with her for a couple of days, but he still choose the mother.

Like I mention in the beginning it was the Raws and I used the lends text translatorrr.
https://manhwasmut.com/manga-as-if-daughter-raw.html

In my opinion -
I think after he spend more time with our FL he did want to stay with her, but with the whole age gap he choose the mother. I think he and the mother ended before she passed away cuz of his guilty conscience.
Btw, I wanna be clear, he did it for a couple of days with our FL, but is cuz of a deal she made with him. She knew it was gonna end when her friend and mother came back from the camping and work trip.
She should look for his mother not the FL that she doesn't even know the name of.
After all, he goes on a killing spree when his mother dies before he got to see her.