My son is being teased please help?

my son is biracial (African American and Caucasian). him being biracial is not what he is being teased about. he is being teased because he looks like the singer Prince Rogers Nelson. i have always thought that my son looked like prince since he was very little. now he is 11 and the resemblance is scary. the only difference is that my son has blue eyes. but otherwise he looks just like him it's weird. everyone keeps teasing him about it friends, family etc. he gets really upset sometimes. i tell the family to stop but they don't. what do i do about this?