I choose other because it really isn't my place. I do think that getting turned on by the idea of sucking another guy off and getting penetrated by one does kind of sound like some kind of attraction to me though.
Either way I wouldn't spend too much time trying to classify myself or someone else. I'm really not turned on by the idea of having sex with another guy other than my boyfriend. I am turned on thinking about having sex with another girl. Even then I still say I lean more towards guys. Just to make things easier I call myself bisexual but I really don't put too much thought into it.