This is a very tricky situation. Often when friendships are taken to a sexual place, misunderstandings can occur and someone can get hurt. On a few rarer occassions (my experiences)--two friends can go there and find an ever deeper, more meaningful relationship. My advice would be to tread carefuklly, be clear about what your short and long term expectations are and have your friend do that same. It reads like you have been developing an emotional attachment to him (which, in and of itself is in no way a bad thing); just be careful.