As much as I like yuri, incest is a big no for me. I would be actually happy if the black-haired twin ended up with the red-haired guy and the grey-haired twin found some girlfriend. I can't really see where this is heading, but I will continue to read it because I love the art style. But incest is a big turn-off. Same-sex incest is better than opposite-sex incest, but it still feels wrong.