-both haruto and shun love kiyohisa
-the parents try to force haruto and shun together
-haruto knows kiyohisa loves shun so haruto lets them mate/pair together
-mom reveals that if haruto and shun mate they would make a superior alpha kid
-haruto is disgusted and decides to protect his friends by pretending to follow his mom's orders
yes, this page in the bottom left (but be careful there is a sex scene): http://www.mangago.zone/read-manga/yuujou_haramase_triangle/nbt/mpn_chapter-2187537/pg-26/
i'm still not sure if i understand what the black room/mirror is so i'll just leave my thoughts here.
-the mirror power is similar to a demon maybe?? malice manifests as a demon which uses mirrors as the medium. but specifically you need a dark room with mirrors in order to realize/manifest your malice for the first time.
-i especially get the feeling of a demon contract because when they made that wish that they could be alone was when the malice in the mirror appeared.
-also mirrors act as portals to another realm where malice/demonic entities were from and could take the bodies. That's why you can see other bodies in the mirror? but im not sure why bloody hands are the physical form of malice.
-the last time we saw the malice it was a complete reflection but with the red eyes, kind of like a demon that is possessing someone.