Hi,
It is very common today to find people who do the friends with benefits because they feel they don’t want commitment or hassle of a relationship. That may of been the way it began. I see that he has developed feelings for you over time but its really hard to break certain patterns that have been placed. That’s not something that he is thinking right now but he does have feelings for you. I think you should just straight approach him and judge according to his response. That will tell you whether you should move forward or not. Have you brought it up before?