my brother is stealing my underwear

so recently i noticed a certain pair of my underwear has gone missing, i was kinda upset cuz it was my fave pair but i didn’t know if it were in my dirty laundry or not so i decided to wait until it was washed then see if i had it then. i just remembered last night, i did NOT see this pair when i did my laundry a few days ago… so i told my mom. my brother has a history of stealing underwear and when i was younger he’d steal my swimsuit bottoms and wear them, so my mom checked his room. we found a hidden collection of over 20 pairs under his bed, barely any of those were mine. i can’t stop thinking about this as i am so disgusted and i just cannot believe it. i really only care about him stealing MY underwear, most of the pairs i saw are not at all mine but probably from whoever’s houses he hangs out at with his friends.

one time, i’d noticed a 7 pack of thongs was shortened down to 2 pairs because he had stolen them all. i told my mom and she went and found some of mine along with many others just like we did last night. my dad has talked to him about this so many times and he still hasn’t stopped. it’s truly disgusting and i cannot believe as an 18 year old who is turning 19 this year, is stealing women’s underwear ESPECIALLY from his own sister. i think he needs more therapy than me, and i have mental issues.🤦‍♀️ i’m truly tired of this and constantly having to get new underwear in replacement of the pairs i lost. will he ever stop? or does my family have to humiliate him out of doing it….

edit: i’d like it to be evident in the original post rather not in the comments since this gained lots of attention unlike i thought it would, that i had not thought about this being/becoming a bigger problem than it seemed to be to me and my family. sadly this is my reality and what i have to go through constantly, having to hide my own underwear in my own room and hiding it in my laundry so i don’t have to worry about them going missing. everyone’s reactions and comments have helped me realize that this is in fact a serious issue, and i’ll be sitting my parents down to talk to them about how violating this is for me. i’m 16 years old, i shouldn’t have to worry about my ADULT brother stealing my underwear, or have to even hide any of my clothing from him. didn’t mean to come off as if it weren’t serious, but it’s just continued for years and i’ve feel like i’ve just suppressed the thought of it being something more serious by me just simply being weirded out. but since he is 18 years old, turning 19 and i am still a minor, i’m going to be sure that my parents put him in some sort of therapy about this. it’s seriously not okay, and they’ve enabled it for too long by not doing a single serious thing about it. if they don’t do anything about this, i will be filing a report against him as i am not going to continue living like this.