My dad won't let me see her anymore

Ok well my best friend in the whole world has a new boyfreind who is like 5 years older than her and is mexican and she has been disstracted by him to much. And well my dad is so mean he found out that she has this boy friend and he todally freaked and know I'm not aloud to go over to her house anymore,talk to her on the phone and I can't even talk to her at school I'm so mad I know he is trying to protect me and he loves me but I'm like so mad!!! What can I do

tell him you have nothing to do with the guy your friend is with, you disagree about the relstionship aswell but since you cant change her mind you still want to be friends with her.