AIO? I don’t want my autistic brother at my house

title is a little clickbaity because his autism has nothing to do with my animosity towards my brother(15). i’ve felt uncomfortable around him for years, with this being the first time i have expressed and placed a boundary. he has a history of being aggressive, spends 90% of his awake time watching youtube or on roblox which usually results in a rage fit. my parents have heavily neglected his development and has been “homeschooled” for the past decade. he has an anxiety disorder, depression, and an explosive mood disorder, alongside his autism. i don’t know if this is relevant or not.

a few months ago my mother and i were searching through the family computer trying to find evidence of infidelity in her marriage, instead we found a google search history of “cat fellatio, feline genitalia, cat vagina” along with other weird teenage boy stuff. my mother did not address any of this and acted like she didn’t see it. ok, whatever.

my daughter also has extreme stranger danger towards him, latching onto me or her dad when he’s in sight. there’s been no time where they’ve been left in the same room alone together so i have no reason to think anything happened between them besides any vibes my toddler picked up.

i recently weaned my child from nursing but whenever i would visit my family home, my brother would come into the common spaces to hang out. i would be nursing frequently, on demand. my brother would watch and he is not subtle. this would lead to him “adjusting himself” often until he would eventually leave the room. this same thing would happen a few more times when i would simply be in the room playing with my toddlers and he would be adjusting.

is this normal teenage boy behavior? it really feels like my mother is choosing to ignore these red flags and excuse his behavior. as a mom, he makes my anxiety skyrocket.

thanks to anyone who reads. hopefully i don’t come off as an AH.