Caught my little brother in my knicker drawer and now idk what to do.

So i live at home with my parents and 2 brothers one older brother and one younger brother and for the last few weeks I've noticed that some of my knickers have gone missing like someone has been in my knicker drawer and taken them out, thry would go missing then turn up a few days later back in my drawer i didn't really think to much of it but I knew someone took them.

The other day I was sat downstairs minding my own business when I thought i heard someone go into my room and I know it wasn't my older brother as he was out and so was my parents so it had to me my little brother so I went up to check, i slowly walked to my room trying not to make a sound my bedroom door was slightly open and I looked in through the gap and could see my little brother going through my knicker drawer, I was shocked and didn't know what to do .

I was just watching him for a moment and saw him take a pair of my knickers and put them in his pocket i was so shocked to find out it was my little brother stealing my knickers, he closed my knicker drawer and left my room is quickly had to hide in the bathroom so he didn't know I was watching him steal my knickers.

I wasn't sure if I should have gone into his room to talk to him about what I saw and I still don't know now if I should talk to him? Should I let me keep doing it or should I talk to him about it ?