Notice: Please, please, please - get your kids out now! Lago Vista is basically a suburb of Austin (San Francisco West, we call it), so I'm going to assume that most of the children there are already aware of the gay subculture.
That said, in the small central TX towns near me, a child is more likely to be exposed to a homosexual/marxist philosphy type agenda in one of the parochial schools of the major religious denominations, than in public school.
A. Homeschooling is cheaper than any parochial school, and you know what your kid is being taught.
B. Being aware of homosexuals is not the same as being indoctrinated into the glories of homosexuality. GLSEN is a powerful organization dedicated to changing the cultural and moral foundation of the US. Have you read any of the links EdReform and Scripter post daily? Being aware is nothing. Being exposed to a conscious pattern of pro-homosexual dogma throughout the entire school life of a child is entirely different, and exceedingly dangerous.
In CA, it has been mandatory since 2001 to teach children about homosexuality in a positive light K-12. And that's just a start.