People choose to be gay and it's very easy to prove. I'll prove it right now.
If homosexuality is something you are "born with" then why do straight men have sex with transsexuals?
Because they are gay? Then why don't they have sex with other men?
What is the biological gender of a transsexual woman? Male.
You literally can't argue this. Homosexuality is a choice - conscious or unconscious which is based on environmental factors. Period.