Thing is, it's most likely the endgame anyway. Aya is tired of Haruki's shit and rather have a toxic "replacement play" relationship with Kuro. Unless Kuro has a change of heart to decide to throw back Aya into Haruki, i don't see how Aya will go back to Haruki.
Yeah. The adult seduced a virgin girl into her house and raped her, then slapped her, had sex and run away again. Even the author tried to make it look like romantical unforbidden love, in my opinion I can see only a pedophile and girl with stockholm syndrome. If the woman are man instead, the ending might be a girl get pregnant. This manga will be a shitty hentai.