Im Not Comfortable with my Big Brother
So My brother naturally isn't well in the head like he's aware of so many things normally, but acts like a child and my mom favors him more than anything due to some past issue. So he's a very awkward person, I'm 17 and he's 31. He's very hyper and touchy and says A lot of inappropriate things. He's also been alone and never had a girlfriend which throws me to the fact that this all coming from his desperate-ness of having no sexual intercourse or even a simple relationship with a girl. So 1, When I was 12-13 my sister would invite her male friends over, they were 17-18 so my brother was like 27 or so and my sisters friends were very inappropriate and would say sexual things to me and my friends and even one groped me and touched my hips at one point, but I was not aware of it being "bad" at the time, I obviously know now, but that gave me a bad trauma and now Im uncomfortable around all males older than me. Okay but at the time as well my brother would hit on young minor girls, my friends were my same age, 12-13 and seeing a 27 year old hit on them made me uncomfortable and even now that he's 31 he still hit on my friends and said he wanted to marry them and wait till their 18 and they were sexy and attractive while they were 16-17 and I had to stop inviting them because he kept looking at them, giggling all over the place and just being a creep over all. He never touches, but he's touchy with his family, not sexually, but you know a pat or rub on the shoulder, hugs, arm around shoulder, nothing ever you could say is super sexual. But Im wo uncomfortable with it and he tend to space out and look at me or down at me and I start getting uncomfortable and curse him out causing my mom to panic and want to prettt much murder me for yelling at her precious angle. He even slipped a long time ago and said to me and my sister that we masturbate or he can imagine us using stuff to do so and that we all do it cause its normal and such nasty stuff I cant stand hearing from a grown male family member or even any damn stranger. The last thing he said to me 1 year ago was that I have a big but which made me even more uncomfortable and I cant have a option of telling him to stop cause he'll be like "What? i didnt do anything what's wrong with you?" Or keep joking around about it. And telling my mom? Its like telling A only child bearing mother that their attacking her only child in the street. Her favouritism is huge so she'll think we hate him or that he didn't do anything wrong. She says that we hate him and doesn't want us going out with him because I yell at him when he's looking at me and smiling like such a creep and I can't even wear clothing that shows 1% of skin or anything because he just keeps looking and idc if he doesn't mean it sexually but he doesn't stop and it's just killing me. I do have a therapist but that's not working out well and I'll be switching soon as my problem isn't being solved. If anyone can help me think of something please do. He also has a therapist but my mom and grandma baby him so they won't say any of the stuff I see from my own eyes. Any help would be great, thank you.