When she ever used Kyou to distract herself from Fuyuki? At her birthday? At that time she really try to respond Kyou's feelings seriously after he reveal his true feelings. And before that too, she tried to really likes him whether it's successful or not. He is the one that kind of manipulate Eri to date him by saying it's okay to prioritize Fuyuki like that. And then he's mad that she act like she said she would?The girl said it all. Kyou is to blame for sure, but Eri just "used him" to try to distract herself from thinking about Fuyuki. And that hurt Kyou a lot.
They are both bad people, each in their way
Fuyuki I love youIf you want to act like a tragic heroin so much, could you please do it with someone else
it’s v manipulative & it also doesn’t help that eri has literally referred to fuyuki as her “possession.” it definitely feels like she’s using this opportunity to prove to herself that she has some kind of effect or deeper bond w fuyuki over senpaiI can't help but feel that Eri is maybe just feeling insecure and is selfishly projecting onto Fuyuki who she now knows is gay, but I really hope I'm wrong and this is a genuine realisation of her feelings. Kinda out of pocket to kiss someone in a "relationship" though (maybe a bit of revenge idk), I bet Fuyuki will be very confused next chapter.