Lmao "twincest = wincest" been a long time since I heard that one. And the tag "bromance" this adds a whole new meaning to bromance idk man lol. Well, Im the cat. Curiosity killed me.
...Interesting. The incest brought the rating for it down but the concept of forbidden blood and the canon of how possessive Yukio is over Rin is put to work here, so there was some research.