"ENDA, what might be more appropriately called 'The Cross-Dresser Protection Act,' takes the bedroom into the workplace and unfairly burdens employers to know about their employee's sexual lives. This major expansion of federal power over the workplace places an unnecessary burden on small businesses and local communities.
First, as Vanessa notes, this reveals absolutely nothing about any employee's "sexual lives". Knowing that an employee is trans (or a "cross-dresser") doesn't say anything about one's sexual practices (including whether one is gay, straight, or bi). It's the FRC that is sexualizing this, not anybody else.
But even taking the FRC's misguided analysis at face value, what it boils down to is that employers will be "burdened" by the knowledge that someone that they talk to might be ... having sex? Having teh gay sex? Whatever it is, I'm not sure how this abstract knowledge rises to the level of cognizable harm.