There is no gay gene and identical twin studies prove it.
If it were genetic, both twins share the same genetic code, and if one is gay, if it is genetically determined, the other would always be gay 100% of the time.
Yet in real world studies of identical twins where one is gay (observed by both gay (pro-gay) and non-gay researchers, the other identical twin is gay only about 50% of the time.
To be immutable, genetic, cannot NOT be gay, the identical twin would have to be gay 100% of the time. Same genetic code would not allow the other twin NOT to be gay if genetics force one to be gay or not.