"We can still be friends..."  

Wow, I appreciate the sound of that phrase, but you have to be true to yourself and if 'friends is what you have ... today... then that is what you have.
There may come a day when there is more, but you "can't make your heart feel something it won't", so go with the friendship and keep him there. There is great value in a good friend of the opposite gender.

From personal experience I can tell you that if you continue with the relationship sooner or later you will both be hurt.

I married at 23. I did not know it at the time but this is how my wife felt. She never dated in High school and had really nothing to compare me too. But she knew she didn't feel right. I was aware of this but it was so right for me that I talked her into marriage.

It would have hurt to loose her then but not like it did later. We were married 37 years. Around year 30 I found out that she had several affairs back early in our marriage. It like to killed me but after seeing a crises councilor I convinced myself that, okay we can do this. Our kids were out of the house and not that many years until retirement. We were always good friends so we continued on.

All went well until life circumstance put a strain on the marriage we did have and she had another affair. I divorced her.

While we did have two children and now 4 grandchildren which I am so great-full for our relationship was never what it should have been. I will always wonder what it would have been like if she had felt the same as I felt for her.

So please understand you can hurt him now or later or if you don't hurt him now, and continue on, sooner or later you will feel cheated. Go find that one that will give you the feeling you need.