what happen last chapter are objectively awful yes, no one gonna deny and defend that
though seeing it from both side POV are better discussion than just "he's rapist, off with his head", it just soo "modern" and "puritan"
Fio are ex-guy, she know the situation and fully know alto condition and the fact that he restrained himself seriously, pretty clear she hate the idea of the guy being miserable and hurting himself after he saved her from certain death, she want to pay him back
while on Alto PoV, he's pretty much restraining himself out of sheer conviction and Fio ruin it all by "offering" her self, even with pre amble "nothing happened tonight, nobody remember a thing, do what you want" to add, it's really throwing meat to a starving dog
Fio also admit, what she did are dangerous and reckless, alto action definitely beyond what she imagine, afterall, he never act like that ever, even after being surrounded by his harem 24/7, fio are the one that "trigger the flag", when she notice the strange situation, she try to back off, taking back her "consent" midway, but the guy literally under subtance, him actually listen to any reasoning are wishful thinking
the guy clearly have no idea how to interact with a girl, socially awkward, and mess up under influence of subtances, what he want are just to apologize, maybe with gift, maybe with other action that can raise the chance to success, i believe he didn't apologize right away pretty make sense considering he is socially awkward, saying sorry after all that must be pretty tense situation, not too mention there's also a chance the apology are taken badly if he just say sorry non-chalantly