As far as I can tell, the pathogen hypothesis makes the most sense. I obviously don't believe there is some "gay bug," but it could very well be some kind of virus that rewires the brain, similarly to what toxo does. I guess the next step would be to figure out if it can be contagious. And that's pretty much it. I just want to know more before I can decide if gays should be allowed to adopt kids.
So you think being gay is a disease?
You are ignoring several decades of research showing that children raised in households of two lesbian mothers or two gay fathers have "no higher percentage of gay children" than heterosexual couples. See
Gay Parents and Their Children]. This will only show the first page, but includes the phrase I quoted here.
If you need any more convincing I'll try to find time to log into our university library and download some full studies for you. You should go to Google Scholar and search on the phrase "do same sex parents raise gay children." I did a few minutes ago, and found a plethora of research refuting your concerns.