This is sort of the long agurment of the peeps if you ask me. But the thing is they are not related the main FL knows it but the ML does not. If we go by the first intro.
At chapt 17 or 18. There's a chance she doesn't know ALL the things that will happen in og plot. There's gonna be something that will trigger to remember a memory.
Also, Ml really needs to stop unnecessary jealousy
The ppl who are complaining about the mommy milkers haven't been into nhentai. I've seen far more worse and this is just rookie work for others