
yo idrc if he did it for/bcs of his ability but the fourth one was really uncomfortable and yeah shouto might not had any sexual intention but he also wanted for katsuki to grow up quickly – waiting for someone to be of age to do things (usually sexual stuff) w them = grooming.
the third one was cute tho jealous uni student katsuki aND working adult shouto ugh

kinda liked the ending w her trying new things, following her heart and shit but this isn't exactly polyamory. as people have already said, this is an open relationship. the author should have research first what is polyamory instead of blindly making a story where they basically have sex w the other in the relationship and only know/be/have 40% of the partner. polyamory is 100% w everyone in the relationship and not just about sex.
the plot could've been good if it had been explored more.
oh well that's cute