VMBREADERS! I Caught My Brother's Friend Smelling My Pánties; What Should I Do?

My Friends Brother who is between 17 or 18 came for a Sleepover, am 25 . My Parents were out and wanted me to pretty much 'babysit' them while they were away, time went by and I wanted to go for a Walk. As I got back, I went back to my room and I saw with my own eyes my Brother's Friend smelling my underwear from my laundry basket I was so shocked I stubbornly cleared my throat and he turned away swiftly and looked at me, and couldn't say a word,dropped my panties and left with shame.

Later that day, I sneakily went into my brother Friend's bag to see if he took anything, as I opened his bag i saw my Brá and 2 of my Underwear, I just got so Furious but couldn't do much. What should I do about my brother's friend and is it normal? To me sniffing pánties is just disgusting, You are smelling something that someone rubs their Cores on.