Help! How can I stop my dad from shaving my head??

I am 14 and I just got head lice. My dad is gonna shave my head! I love my hair! It is a lot like zac efron's! My dad knows there are products I could use but he keeps saying, it's time to cut that long hair. How can I stop him? Btw, I will be a freshman in hs and want to look good for school. Help!!!