When I have a crush on someone, it means I'm interested in them and want to get to know them better. When I love someone, it means I care about them and want them to be happy. I feel protective towards them and genuinely care. When I'm really 'in love' with someone, it becomes even more intense, and I can't stand the thought of living without them.
I had lots of crushes, quite a few people I loved, some I've been in love with ... but only one I ever wanted to marry. So I did. And we are very, very happy together in our marriage.
So in answer to your question, if you only have a crush on the guy, I don't believe you should want to marry him. You haven't said you love him and you haven't said you're in love with him so why would you want to marry the guy? And yes, I believe he could really love you without wanting to marry you.
I suggest you either keep enjoying the guy's company and wait and see if you fall in love with each other and someday discover you're both so in love you want to marry, or find another guy.