” it only matters what we decide is “normal.” “
What arouses a person is beyond that person’s control. If you have decided that is not true, we’re done here.
That is just so much bull$&*%. That presumes that we are nothing more than biological machines without concious control over any portion of our responses. I reject that position as being simplistic and foolish. People can "control" their responses to many things - including sexuality. The fact that many won't, or feel that they can't, doesn't mean squat. Likewise, your refusal to consider anything else but "it's written in stone by biology" makes no sense in light of the fact that man is both the most adaptable animal in nature and the only one who has sufficient insight to even consider moderating his or her behavior beyond that which nature demands.
Even so; what of it? If a man desires sex with 3 year olds are we to accept it as normal merely because he, or others, say that his desire is inborn? I think not. If I need not accept it for persons who desire 3 year olds, I need not accept it for persons who desire others of the same sex.