Do I give him shit?!

My fiancé's 13 y/o cousin who I'm close to has a friend who I have a good relationship with as well. Today her friend who's also 13 told me that a guy in college (he's 19) in our area tried to hit her up on instagram. After she let him know her age he said "so no one has to know". I found his instagram and I just want to give him shit for hitting on a little girl that JUST graduated from grade 8 and felt creeped out by him. Do I do it?

She does have older brothers but she doesn't talk to them about this stuff and I don't want to overstep my bounds but I feel like someone needs to put this guy in his place. What do you guys think?