My 17 year old younger brother is dating a really good friend of mine he is 23, and I don't want him to. He is a good friend but he is not a good boyfriend(he cheats) drives a motorcycle, he is basically a bad boy. He is not good enough for my brother at all, my brother deserves so much better. I don't know if I should tell him that I don't want him dating my brother or tell my brother about the type of guy he is? What would you do if a guy like this was dating your younger brother?