Not a joke: My little bro has been stealing my underwear. What should I do?

I really don't wanna just call him out on this, can't imagine how weird things would be between us after that. But I really don't want him to continue to borrow my panties to do god-knows-what with. He's in his mid-teens and I'm in my early 20s. First noticed a few months ago that my underwear drawer had been ransacked (was kind of a fluke that I noticed things were out of place, but I knew for sure that day that a certain bra was in a certain place and when I looked the next time it had definitely been moved).

Thought maybe my mom had been looking for weed or something (lol she knows i smoke, i actually thought maybe she'd wanted to borrow some but I never even bothered to say anything to her). The next time I noticed anything weird was when I went to do laundry and a pair of panties that I KNEW I'd worn a couple nights before was like totally MIA,

This happened one more time and then I was really confused. I knew my sister wasn't borrowing my dirty underwear lol eww, but I asked her about it anyway and she's the one who mentioned that maybe our bro took it. He's clearly interested in girls now but is a total introvert who hasn't had any luck actually dating or whatever as far as we know.

So finally I snooped and found a few pairs of my panties and a couple that I think were my sisters in his dresser! I'm more than a little freaked out by this, but I guess maybe it could be normal? I've heard of guys wanting to sniff panties and wear them and stuff before, but the thought of my brother doing this is obviously pretty shocking. Bottom line is I don't want to make things permanently awkward between us, because I'm sure he'd be really embarrassed if I confronted him. But I also would feel too weird about allowing him to keep doing this.
Not a joke: My little bro has been stealing my underwear. What should I do?
Add Opinion