My little brother is becoming a horrible person.

Hi everyone, thanks in advance for reading. This whole situation (a.k.a. my brother) makes me uncomfortable, angry, and confused. Any advice/opinions are welcome, as I just don’t know what to do. This is a sibling story, and as with any family dynamic, this is a long one with many layers. 

I, 23F, have a 21M brother and no other siblings. We fought a lot growing up. Basically any time we interacted, we were fighting. Our fights plateaued when they got physical: there was one where he grabbed me and slammed me against a wall and another punching me square in the nose when we were 16/17. My parents did their best to keep us separated after that one. I moved out for college at 17, and it became a lot easier to take my mom’s advice to ignore him. Each time I’d visit, he would try his old tactics to rile me up, but I’d do my best to divert my attention or remove myself from the conversation if necessary. He caught on after about a year and mostly stopped pestering. We didn’t talk much while I was at college.

To sum up a very long story, while I was at college, my brother flunked out of two colleges and ended up back at home. Before college, he had barely graduated high school and made my parents’ lives a nightmare, having to incentivize him to do the bare minimum to pass. Stupid incentives exist to this day; my mom had to pay my brother to dog-sit OUR dog overnight. He gaslit her into justifying paying him because “she would’ve paid someone else if he couldn’t watch her.” For the last few years, he has been living under my parents’ roof while they cook his meals and do his laundry. He does not work. He does not party. He does not travel. He does not go to the gym. To be honest, I have absolutely no idea what he spends his time doing. It is a bit sad, and I would feel bad for him if he weren’t such an asshole.

Things took a turn for the worse this spring, starting with when he opted out of attending my graduation. To make matters worse, my mom (who now regrets telling me this) told me that a family member of ours had asked him what my degree was in - he didn’t know. He hadn’t paid enough attention to remember. I was upset to say the least and knew I would be avoiding him entirely the next time I came home.

Between graduation and starting work I planned on spending my few days off at home. He made his first appearance the second day I was home while my parents and I were chatting about all the world’s problems. My brother was fixing himself something to eat when he chimed into our conversation. This conversation was emotionally traumatizing for me, so I will recount what I can remember. Throughout one lengthy conversation, my brother shared opinions I didn’t know he had but knew for sure he didn’t get from my parents, as they were as shocked to hear the words come out of his mouth as I was. He was ranting about how modern racism is a myth, white privilege isn’t real, transgenderism is mental illness, misogyny is “the woman’s fault” or “traditional values misunderstood,” and he disagreed with “my interpretation” of the disadvantage of being female in my male-dominated industry. That is the very concise, PG version of the conversation.

I left in tears. I didn’t recognize my brother. My parents would NEVER have led him to believe any of that hateful garbage. Think of the most misogynistic male influencers/politicians, and they were who my brother listed as his trusted sources. In all this free time he had, he chose to donate his attention to these misogynistic, racist, homo/transphobic people and their verbal diarrhea. How and when did this happen? I went for a drive to reflect and put together his pattern of behavior in my head. To my shocking surprise, he sent me a long, unprompted text apologizing, admitted he needs to get offline, and was even crying when I came home. I’d been so put off by his behavior that I had a hard time believing his apology. I left home earlier than I’d planned, and we didn’t speak for months. 

Here’s where my parents come in. Since the spring, my parents and I have had some tough conversations. IMO, my mom has given up. I’ve heard her say multiple times, “I don’t know what I did wrong,” and it breaks my heart. She feels defeated. My dad, on the other hand, is completely delusional. I’ve tried to tell him multiple times that HE has to do something about my brother because he will not listen to my mom as he doesn’t respect her. I don’t think he respects my dad either, but my dad’s angry voice is scarier than my mom’s, at least. My dad thinks my brother is “figuring things out” and thinks he “doesn’t really believe those things he said” during our last fight. He doesn’t stick up for my mom when my brother is rude to her, and that hurts her too. I can tell this whole situation makes my dad very uncomfortable. My brother is emotionally draining my parents.

I have recently moved to a different country, so I don’t have to worry as much about seeing my brother, but I am genuinely worried that he will shave off a significant number of years from my parents’ lifespans. In most ways I can think of, he is a bad person, getting worse. I feel an obligation as his only sibling to do something about it and get him help, but there are a lot of details I had to omit that keep me believing he wouldn’t accept it anyway. I feel like I’ve been robbed of a brother and instead have a stranger with whom I happen to share parents. Help!

TL;DR: What can an older sister do about her younger brother (with a history of aggression) who is becoming a horrible person and driving her parents crazy? Does she have to do anything if she’s moved away?