Keep your underwear locked up and invest in a lock for your room. You shouldn't have to do so, but if it were me I would no longer feel safe in my own home with that pervert around. If your parents still don't get the message that they're not doing enough, send the bill to your parents.

Step 1: Get some very strong chilli-powder. Step 2: Select a few pieces of underwear to sacrifice. Step 3: Apply powder generously to the underwear. Step 4: Lock away all your underwear, except those few. Don't make it look obvious, though. Keep them where you use to. Step 5: Entertainment for the whole family.

This is going to be one pregnancy that's very difficult to 'splain.

Don't use chili powder it's messy and is noticeable ,instead go get some cinnamon oil just make sure you use rubber gloves when applying it cuz it will burn the skin easily in pure form 😈 he won't be missing with none of your stuff after that 😁 but you will have to sacrifice some underwear because they will no longer be usable once they've come in contact with cinnamon oil it can't be washed out very easily. I normally wouldn't endorse revenge but that is seriously sick and messed up if one of my kids was doing something like that, I would have kicked their ass to the curb.

Get a lock with a key for your room, and starting doing (and watching) your own laundry if you're not already. Tell your parents that either they or he need to buy him a pack of underwear to jerk off into, and that if you catch him with yours again you're going to start reporting the incidents to the police so they have a record of harassment and theft long before he escalates this into something worse. Limit the contact you have with your brother.

punishing is not gonna help, he likes that stuff and won’t stop as long as he has access to your underwear