@Piggy Lover Sorry to pitch in, well Yoohyun has always been weird by normal people's standard since he is a natural born S rank, while Yoojin bearing the nurturer, later upgraded to perfect nurturer. With these two factors, their parents being weirded out by Yoohyun is enough to distance themselves from him leading to Yoojin being more caring towards his little brother eventually with this situation and dynamic, their parents grew closer at the due to blaming themselves for being bad parents as they feel they failed their two sons leading to going out more together. So basically they abandoned them physically. I think my explanation is awry but that's the gist of it. They still did supported them financially but their presence is virtually non-existent to put it simply. Thus the brother's view of their family is exclusively to each other. An example of broken/disfunctional family dynamic. This is my understanding after reading the LN so please go easy on me, pretty please?