Is it wrong to love my brother?

Yoongi is a boy that is very shy and doesn't like showing his body for anyone, he doesn't think he is particularly good looking. His dad marries another woman, this means that Yoongi may have a new step sibling. So when it comes to the day that the new woman moves into the house he finds out he has a new step sibling, who is Jungkook. Jungkook does photography at school, because he liked photography and he liked the fact that you can turn anything into something beautiful, and tell a story with it. Yoongi is made to share his bedroom with Jungkook, they now have a bunk bed in the room and they have to add all of Jungkooks stuff to the room, his clothes, his ornaments and his shoes. Jungkook may talk to people and be open about everything, however, he is a complete sadist. He loves seeing people in pain, inflicting the pain on others, putting people down, calling people names and degrading them. That was just him as he hadn't had the perfect life with his mothers ex husband, he was beaten by him ever since he was little, so he thought that it was right as his mother never stopped it. Jungkook was a male who had a mental health problem called bipolar, and that's what caused his sadistic ways. When Jungkook had taken his pills, he was a fine and happy person, but he was always hiding his past life and everything that he had suffered, he was the complete opposite to Yoongi. Yoongi had a good life, his father had gave him a wonderful, happy life. But, his mother died whilst giving birth to Yoongi, so he grew up without a mother. Getting used to a new mother figure would be hard as he had never had one, but also, dealing with a new step brother would be harder. Once Jungkook and his mother move into the Daegu home, they take a few days to properly settle down and once they're settled, Jungkook starts hid photography course in the local university. However, he needs a model and he goes home and chooses Yoongi because he doesn't know anyone else. Yoongi is hesitant and says "No", however, Jungkook wouldn't take no for an answer, so he gets a little pissed and tries to persuade the male to be his model, he is good with that because of his sadistic ways. Finally, Yoongi says yes to the male and becomes his model, however, Jungkook did not want normal pictures taken, he wanted darker photos taken with even more meaning than light photos mean. For some reasons, through all the photos, Yoongi starts to fall for Jungkooks dark ways, he started to realise that the male was sadistic, however, he liked the excitement. Yoongi has been strictly vanilla, which meant plain sex. however, Jungkook offers something more exciting, more challenging and can induce more pleasure. One day, when their parents were away, the photoshoot was a dark and pleasurable shoot, the shoot was more intimate and then it just happened. They ended up having sexual intercourse and Yoongi sees how sadistic Jungkook really is, seeing the dominance and lust that Jungkook emitted and then gave to Yoongi was phenomenal. From that day onwards, they get closer and closer, hiding their actions from their parents as it would be so wrong if they found out. However, they keep it a secret as Yoongi has work and Jungkook has school.