My friend flashed me in the locker room. What should I do?

I am 13 and in 7th too im a gurl but ik the guys and im such a tomboy tht ik tht he meant it as a joke and all idiots sag lyk him so it mitv been lyk an accident but u shld ask him. B lyk y the hell did u show ur junk 2 me?! Now at least u hv proof of him hvn lil... Um stuff. ;)