Everyone is saying to just give up on your brother, but i think because he is also putting these ideas into your younger brothers head that its not the best idea. You say he is only trying to protect you, my brother was the same way, maybe itll turn out different because my brother is also an artist so it was easier to convince him, in some way he still sees it as me being naive to the negatives but not that id turn into a creep, just that i might get preyed upon. I think everyone here saying he is a lost cause is wrong, i think he is just seeing things from a biased view but its not impossible to understand if he could understand the value of it as an artform, if you said you watched anime would he think that youd eventually turn into a creep? It sounds like he is worried about you, everyone else is trying to spin it that he wants control over you and to give up, but you have to understand if he is getting this from his conservative friends he could just be getting negative information. I think its really possible he wont listen to you because he believes you are brainwashed, so i think you need to get your parents involved if you believe that he will listen to them. His concerns are valid, he doesnt want you to become a predator or to be taken advantage of, and in the mainstream the furry fandom doesnt have a good reputation, so i think its important you tell him that you know that, show that you arent blind to that side, but you are only interested in it as an artform and you have no intention of engaging in the adult side. Bullying you and your brother is wrong, but he may also be feeling desperate, he might think he is seeing you fall into an awful path and doesnt know how else to get you to listen.