[Just Peachy.]

You do have the right to your independence. But seeing as you're 15, your parents reserve the right to know things going on in your life. This is more applicable if you were any sort of danger, though. In this case, if you want your parents to know, then tell them. It's not completely necessary to tell them now, but eventually you should. Preface it by telling them you understand the danger of having online friendships, and tell them what you do to protect yourself online. Parents tend to like that sort of stuff. If they get upset or seem to be uneasy about the whole situation, perhaps have them Skype with him. That might ease their mind if they can personally talk to him.