all because they have an intrest that you do not like you want to change who he is instead of being forward to him that you don't want him to share that stuff? You sir, are NOT a good friend you are a horrible horrible person and it may be better for the both of you if do one of these things:
A. be more open/honest and tell him how you feel while trying to be more accepting that he's different from you
B. don't be firends with him anymore.