Should I tell my parents?

I know the way I asked this question sounds a bit extreme, but it sort of fits. My 10-year-old brother in 4th grade is friends with this kid in the seventh grade. This kid is my neighbor, so they usually play video games and stuff. but, this kid is known as trouble throughout the neighborhood. He doesn't beat people up (hes a bit overweight), but he can be violent. He has been suspended from school before... I am really wary of this kid, but my dad lets my brother play with him because a. he feels sorry for the kid and b. he is friends with the kid's dad. my brother was showing me a message that he got from the kid over the wii, and i was shocked. this kid had changed the lyrics in santa claus is coming to town to "santa claus is coming to you". it was meant as a joke. my brother had no idea what this meant but i scolded him anyway. should i show my parents this message, and risk my brother hating me forever, or keep quiet?