Discrimination on the basis of sexual orientation is premised on sex-based preferences, assumptions, expectations, stereotypes, or norms. “Sexual orientation” as a concept cannot be defined or understood without reference to sex. A man is referred to as “gay” if he is physically and/or emotionally attracted to other men. A woman is referred to as “lesbian” if she is physically and/or emotionally attracted to other women. Someone is referred to as “heterosexual” or “straight” if he or she is physically and/or emotionally attracted to someone of the opposite-sex. It follows, then, that sexual orientation is inseparable from and inescapably linked to sex and, therefore, that allegations of sexual orientation discrimination involve sex-based considerations.The Commission continued to explain that if an employer fires a man for being in a relationship with another man, but would not fire a woman for being in a relationship with a man, that is treating the male employee differently because of his sex. It's also a natural extension of the "sex stereotyping" theory because heterosexuality is a sex stereotype.
The EEOC's conceptualization of sexual orientation discrimination as entirely within the ambit of sex discrimination is a broader definition of sex discrimination than has been applied by most courts. Courts are generally willing to accept that sex discrimination covers discrimination on the basis of an employee's gender-nonconforming appearance and behavior in the workplace, which may include (for example) claims by gay male employee targeted for feminine mannerisms, or a lesbian employee discriminated against for masculine appearance. But the EEOC's recent interpretation goes beyond this and confirms that discrimination targeting the employee's sexual orientation per se is actionable.
This decision is directly binding only on future enforcement decisions by the EEOC in the context of cases involving the federal government. But, the EEOC's interpretations are often influential on the courts that consider the meaning of sex discrimination under Title VII's application to the private sector, as well what it means as used in other statutes, like Title IX. Thus, even though it doesn't govern the education context, the EEOC's decision helps strengthen arguments by students or school employees who may have been excluded from participation, or fired, or denied admission, or harassed because of their sexual orientation, by giving courts and attorneys a roadmap of persuasive reasoning to follow.