Is it normal to like your best friend who knows your bi?

So here is the deal. My best friend of like 6 or 7 years knows that I am at least bi. I have never had sex with anyone. He tells me I need to make a choice between guys/girls. He told me he would not care either way. My issue is I think have feelings for him but I don't want to risk changing the relationship that we currently have. He used to be homophobic until he met one of my gay friends from school. Now it doesn't seem to bother him. I mean he is the type to always be joking around, telling/asking me to suck his dick. I usually find this to be normal for my friends. However he says it more than others. He's what I would call a man whore lol. Here lately though he says he could care less if he had a chick or not. I would like to tell him how I feel. I just don't want to make him feel uncomfortable. I mean we have always considered each other brothers and I don't want to ruin that. It is to the point where I am so used to having him around that it hurts when hes not. I would do anything for him regardless of how it effects me. I just like seeing him happy. So what should I do here? Is it normal to feel this way?