hmmm i don't really blame the brother. he doesn't know the past like the MC and the MC didn't even tell him the whole truth as to why she doesn't like the villain. so, how can he even understand the severity of the situation? ¯_(ツ)_/¯
Yeah but, she has repeatedly stated that she does not like this person. Yet the brother did not probe to find out why (although MC did mention the villainess spread rumours about her) and after 1 encounter with the handkerchief he was already starting to defend the villianess.
Like if my siblings tood me they did not like a person, who used to be theri friend, I would stand by their decision and not interacted with the said person and let them sort out any misunderstanding themselves.
Girlies instead of MC or the villainess i think MCs brother will make me more angry. Can you all see how dumb that brother is? Bet despite all the warning that brother will still get close to the villain lmao.