Gay straight friend
Friendships between gay and straight men are often assumed to be impossible, given high levels of homophobia among straight men. Many gay and straight men report having friends of a different.
It could be you aren't gay, but just attracted to this one male person. This sort of thing happens. No matter what you decide to, if you in any way pursue this, make sure that he knows that you aren't sure of your feelings. Don't "I love you too" or anything like that until you are damned sure.