This month the US Supreme Court announced it would decide in the current term whether all 50 states must allow same-sex couples to marry. But while legal gay marriage has spread rapidly over the last several years, sex education laws in many states remain in the Dark Ages—even in states where gay marriage is allowed.

Sex education is only mandated for middle or high schoolers in 22 states, but almost every state in the nation has policies governing what teachers should emphasize or avoid if they teach sex ed. In 20 states, this means spelling out how teachers should cover homosexuality: 9 states require that information on sexual orientation be "inclusive," while 11 states have either pro-heterosexual or anti-homosexual biases. Read More