Ok hear me out. I kinda feel like the older brother is not entirely at fault for his behavior. I feel like if we have more context on his background we might understand him more. The vibe I have been getting so far is that he has childhood trauma caused from when he took over for their father when he left, he must have had a hard time, and we don't know if he hates his little brother cause there might be unfair treatment between them(from father/servants). Also his approach to women might be harassing cause he was influenced to be that way (could be because of missing mother figure).
Than again I could be wrong, just a perspective thinking