How To Tell The Parents

Ok, so im 16 almost 17 and i`ve been in a relationship on and off for over a year the thing is my parents dont know because they seriously hate the guy but they have never met him they just think he is to old for me cuz he is 19 and that he is a jerk because he broke my heart the first time we dated. I`ve tried 2 talk 2 them and tell them how i feel but everytime they say if i date him they will take away my car and all kinds of stuff so I have been seeing him behind their back. But he just told me that he wants 2 give me a promise ring for vday because we love eachother and i think when i turn 17 im going 2 tell my parents about us but if they say no then im going 2 move in with him but im afraid that if we move in together and something happens that i cant live there no more i wont be able to go back home but im willing to pick him over my family because i love him so much. Any advice would really help thanks melody