It's definitely a shaky situation he's created. Also you're comment made me curious enough to redownload and sift through her scenes to refresh my memory.
After redownloading and quickly sifting through some of her scenes. Especially the controversial one. I've discovered this:
The MC's relationship with her starts as a simple friendship, he's nice to her because she helped out his (nonbiological) sister and she doesn't know why as she's been bullied her whole life, mc discovers her dad is a piece of shit so he tells her she can stay the night at his apartment, the two are basically close friends at this point (There's not a single H-scene with her before this point either), she then interrogates the MC about why he's so nice to her, reveals she gets paid for sex because her dad doesn't work, she's paying the bills as well as paying for his severe alcoholism, THEN the H-scene option appears as she assumes the MC only cares about her for sex and tries to coax him into a one-night stand. No matter what you choose, a couple days later she walks out of a love hotel with a guy. Then the MC goes to see her situation for himself and also discovers that her mother died during childbirth.
So it at least gives you the option to say no to her which makes me think some of these people are exaggerating a bit because you DO know what she does before being given the option of having sex with her. Another point worth noting is that saying no to her advances gives you MORE POINTS with her than saying yes. In other words skipping the scene is "better" despite this being a porn game and everyone usually doing the opposite.
I also wouldn't say she keeps you at arms length but as close as you would keep a friend. Then randomly telling that friend a dark secret because you have no idea why they're nice to you.
It's still a very controversial choice to include it in an adult game knowing that EVERYONE hates NTR. I'm honestly just biding my time until the next update to her story so I can come to a conclusion on whether or not to dip out and forget about this game. But yeah, that's a slightly more accurate summary of this whole deal.