A 14-YEAR-OLD girl walks into the school locker room to freshen up after soccer practice. She finds her naked 17-year-old classmate - by all outward appearances a young man - doing the same. He is friendly and well-liked, though his quirky dress and hairdos are a much-discussed curiosity.

She knows him from the tutoring program for which he volunteers, and she has appreciated his kindness and helpfulness. But now they appear before one another in the intimate vulnerability of nudity. Neither has any sexual interest in the other, but the situation is nevertheless inherently sexual.

It is the first time that she has been in the presence of a naked man; she had intended not to be for quite some time. It is not prudish to say that she can no longer look at him the same way (nor can he look at her the same way) - it is a fact of our psychology. The tutoring relationship becomes awkward, and is soon ended; the exposition of the naked body to another cannot be undone any more than shattered glass can be reassembled.

She complains to the high-school administration. With neither malice nor judgment, she explains that his sharing of the girls' locker room is not just personally uncomfortable, but it violates her expectation of most personal privacy and undermines the friend relationship she had hoped to cultivate. Locker-room privacy shields would be only a superficial solution, she explains: there would still be a naked man only a few inches away.

She is formally reprimanded for her intolerance. He identifies as a transgender female - it is his "gender identity" that, despite having male organs, he is in fact a woman - and her unwillingness to accommodate this disposition is considered a serious violation of his right to whatever facilities he desires.

This scenario is playing out right now in many states across the country. Democratic California Gov. Jerry Brown just signed a law aimed specifically at schools, requiring them to permit any student to use any restroom or locker room, no questions asked. And this scenario would play out across Pennsylvania if the recently introduced HB/SB 300 were to be approved by the state Legislature.

HB/SB 300 is being sold as a "sexual orientation and gender identity" employment nondiscrimination bill, but in states and cities with similar ordinances the reach of the law always stretches to bathrooms, locker rooms, dorm rooms and any other public facility traditionally segregated by gender. This bill would elevate the preferences of a tiny subset of Pennsylvanians to a legal right while treating the prevailing preference not to share personal facilities with those of the opposite biological sex as not just unimportant, but irrational and bigoted.

This is not speculation. In the city of Philadelphia's guidance on its "gender identity" ordinance, it describes concerns about sharing personal facilities as based in "unsubstantiated fears and discriminatory attitudes" that employers are legally obligated to attempt to "eliminate." HB/SB 300 would expand this condemnation of common sense across the commonwealth.

Those who experience the sensation that their physical bodies do not match their true gender experience significant hardship, both internally and socially. It is described as a smothering feeling of personal incongruity that most cannot begin to comprehend. I know I cannot. But should we take this rare exception to the human experience and make it the rule? Should we impose on all the people of Pennsylvania a radical and controversial vision of the "gender spectrum" (a phrase used in the Philadelphia document) that really means that our biological sex doesn't matter at all?

After all, why do we have men's and women's locker rooms, restrooms and dorm rooms? Are they a holdover from a bygone era, like facilities segregated by race, or legal employment discrimination against women? No; we have them because men and women are different in ways that are most obvious and relevant in those very personal facilities. We have them because healthy professional and personal relationships between men and women depend on limiting the sexual tension that comes from sharing such spaces.

The eradication of the idea of sexual difference is the ultimate end of proposals like HB/SB 300, whether the sponsors of the bill recognize it or not. And anyone who questions this new paradigm, like the girl who is confronted by a young man's naked body in the locker room, would be not just in violation of state law, but branded a bigot.