parnets dont want me to date till im 18!!!?

okay, my bf is a country boy.... and im a city girl but i wished i lived in the country.. hes always asking me to the movies and out to eat..the otherday he even asked me to his house,, i had to tell him no to that... because my paernts dont no about him.. my dad is a cop and is sooo over protective.. along with my mom.. they both think i shouldnt date anyone till om over 18.. but i really like him... and everytime my mom cees my best friend walkin with her bf. she goes she is way too young to date even tho my mom dated some one 5 years older than her when she was my age... what do i tell her?