I'm 15... And I have a boyfriend. My dad doesn't know about him.. How can I tell my father?

My dad's against me dating, but I have a boyfriend of quite a while. He's a very nice boy, and he's not trying to get . We're both waiting for marriage. He always puts me first and is amazing. I know if my dad would give it a chance and meet him he'd love him. The thing is, he thinks I'm too young. How would I go about bringing up the topic and eventually telling him? I've kept my boyfriend a secret and he's told me that he'd like me to tell my father because he feels bad about the dishonesty. So please help... Thanks in advance! :)