Not a homophobe, just sick of them throwing it up in my face.
As said already, if you are going to go down the "God" road, be prepared to show the gay gene, just as people born with the fat gene are destined to be fat and people born with the murder gene are destined to be murderers. You always have a choice. That was the God-given gift.
Gay people have pretty much been abused, humiliated, and stigmatized for centuries. It's hard to believe someone would willingly choose the life of a pariah if they could help it.
Regarding a gene, I think it's some hormonal condition in the womb.