Is he serious about me?

Isabell • Happy as can be ❤
Its been almost 3 years and I'm still crazy about the same guy. I'm only 16 and he's a few months younger then me. It took him years to make up his mind about me. We broke up 3 times in 3 years (possibly because we didn't talk much). Now its been 1 year since we got back together. He tried really hard to get me back, gave me his face book password everything you can name. Also... 10 months after we both lost pur v cards to each other. I finally got to meet his family (: lastly, he wanted to get engaged. Trust me I know, I'm not going to yet I'm only 16. I just need advise. I really want to last. I don't have I treat in any other guy. My family loves him. I sware he's the one.... Advise... Anything works. I just want us to last <3