Tags: ABO, rape.
Let just say, Teru’s heart isn’t the purest there is. He is a exorcist, but he is no hero, or saint, he has thoughts, and needs, but that boy is sinful, and he knew it. He would go to Hell in a handbasket the moment his breath left him, despite all the good deed he had done on earth, God would never forsake him.
For he had looked at his brother with such ill will.
For he had had the audacity to wish for his brother’s whole body, and soul the moment their little fingers first touched.
For he had treated the boy with every words and actions laced with lustful urges.

For he had dreamt about not just loving and caring the child, but ravishing Kou and filled the him with his seed and force his brother to bear his children.
For, how he let those thoughts get to his hand and slowly, but steadily, the thoughts, the desires, the urges, they got what they want. Teru was corrupted.
And his Kou is ruined.
For he had ruin the only good thing God created. 
But when Teru looked down at his brother after Teru had force himself on him and marked him, he just felt so, right. The light of his life and the fire down his loin, so soft and safe in his arms, stuffed with his love and covered with his scent, he felt content, he felt happiness and hope.
Brothers or not, a mark is a mark, and Kou belonged to him, and to him only, for eternity to come.
So what if he angered God and ended up in hell? In Heaven, or hell, for every seconds passing by this meaningless world, Kou belongs to him and that was the only thing that mattered.