Dating behind parents back?

I'm 18 and my parents are strict arab muslims. I know that I will be expected to marry an arab muslim and I'm fine with that. But I don't want to have my first experience with guys when im 25 and married. I think thats stupid. I met this really nice arab boy, but he is a christian so I know we wont end up getting engaged or anything but I really like him and I want to have fun and experience having a boyfriend. His parents are the same way but he just does whatever and he knows that he would have to marry an arab christian too. But He is so amazing and I love being with him. My parents are the problem though. Last year I had a short relationship with a boy and my mom found out and she grounded me over the summer. I wasnt even allowed to go out of the house. My parents allow me to go out with my girlfriends and stuff but if there are boys there they forbid me to go. Its just very frustrating bc im 18 and not every guy on the planet will want me. How can I make this relationship happen? Talking to them will be impossible for me. Its also very frustrating for my boyfriend too because he wants to go out with me everyday and I tell my parents im going out with my girlfriends but it looks too suspicious if I go out everyday to them. I just feel so trapped. I love and respect my parents but at the same time I want to have fun and live my life!