When he was only 10!!!!??? Holy cow! I have a 10 year old son. He likes pokemon and video games and is just kind of getting into the idea that girls are pretty. I can't imagine an adult doing that to him.... I don't know if I would have been able to keep myself from pulling all her hair out.... Wow, and it to be your friend, that's terrible.
I can see why you are traumatized. Such a terrible betrayal...