Over protective parents date issue please help!?

hi. i seriously need some advice. I'm currently dating a 21 year old and i'm 17 1/2 we're serious. Unfortunately, my parents don't approve they don;t trust me because i use to date a bad boy. My current Bf is real respectful he hasn't disrespected me in anyway and understand that i can't go out. Now my mom and dad don't want him to kiss me or hug me when he comes over to my house. I mean he has never stepped foot in my house when he comes we're just outside. I understand that although i might be 17 1/2 I'm still under age. It really does hurt me because compare him to my ex he is so much better. if my parents keep on acting like this i fear that since, they don't approve of a nice, guy or a bad boy I'm never am going to see the difference of either one. My BF is getting tired of it because we want to go out at least to the theater, and i mean he has even suggested taking my sister just, so my parents could feel so, much better. I'm stuck people. U see i have good grades i'd never fought anyone in school so, i feel like if my parents are over exaggerating. Today he's coming over, and is going to talk to my parents, and he is personally going to ask them if they don't like him he'll step aside so, i won't get in trouble. In other words he'll let me go because he is just so tied of it, and i am too. It hurts me so much because i do love him, and i know he's been so patient i just, wish my parents could understand. The worst part is that I'm tired of crying because of the frustration that my parents are unwilling to trust me. Worst yet is that they have such low image of me when I've done my very best to not misbehave, or disrespect them in any way.