There are many things that can be used as examples against evolution. Sexuality itself (regardless of orientation) for starters, I mean why would something so complicated which involves two organisms to reproduce ever evolve in the first place? Self- replication would be the most 'beneficial' way to reproduce and some organisms do do that.
You say that "you have to be born that way. whether gene or other wise." and yet before the gay movement became trendy and politicised the overwhelming majority of psychologists etc agreed that it was a pathological diversion in the upbringing of the individual, most notably defined as a lack of emotional bonding and connectedness with the biological father/mother and/or the imbalance of the parental relationship itself. So an overbearing mother and an effeminate or weak (or absent) father was a huge common factor in the research subjects. Of course we can't talk about that anymore because it's just not PC. Whatever the 'causes' at this point in time they are largely irrelevant, if you claimed to have the cure for the gay you'd get chased up a tree and burned alive. :)
Also, if I were an evolutionist I would just say that homosexuality was an overpopulation coping mechanism. That objection can, of course be easily overcome as well. :)
In the end, there are heaps of reasons why evolution as commonly taught and understood is 99% philosophy and 1% evidence so no need to get hung up on just one aspect. :)
