
Bro shirayuki is a psycho and I still like him but why did the author need to bring in a younger bro who lust after him

I don't think its lust. We have to take in their environment first, theres no proper way to learn love from something that doesn't have it. It might be weird for us, its a normal type of love for them. (Although I haven't really read the raws so I might need to, because you might be right I was also hella weirded out by that expression.)
Wow that was good. So glad I stumbled upon this (๑•ㅂ•)و✧