[The legality of an action would most certainly have an impact on how one would answer a question, which was the point of discussion.]

Legality has nothing to do with your "sexuality" discussion, would a homo not be attracted to a member of the same sex simply because it was illegal?
Again, sexuality is a behavioral response identical to the dog and the bell, I really don't think the bell was the reason for the response other than association - like the gay man and the association to "getting off", or the female for whatever need they are looking to fill.

[A heterosexual is not going to be stimulated by sexually explicit pictures of people of the same gender. Nor is a homosexual going to be stimulated by sexually explicit pictures of people of the opposite gender]

They would with the right type and amount of conditioning with the right stimulus.