Answer: Absolutely nothing.
It's the hair on heads we are talking about here, not genital hair, OK, so the presence or absence of a specific set of genitalia has nothing at all to do with haircuts. Right? Are you with me so far? Not too complex really. Here is another not-joke for you:
Customer: Can I have a haircut please?
Hairdresser: Have you got a penis?
See, I told you. Not funny. But a situation like this happened to my friend today, and I need to rant.
My friend has short hair, exists mostly wearing jeans and tshirts and is often covered, to a greater or lesser extent, in paint. In fact the paint is often the most memorable feature - I asked at a local cafe is they remembered my friend coming in for coffee and it was when I said "covered in paint" that their eyes lit with recognition and they said 'strong latte no sugar!' or some such. Because unsurprisingly the lovely staff at the cafe are more interested in what someone's regular coffee order is than what genitals they have.
Back to hairdresser. My friend is a woman. She doesn't like labels for herself, but the labels other people ascribe to her might include woman, girl, lesbian, queer, genderqueer, gay, gender non-binary, dyke butch, possibly boi and definitely the one she really hates, shorty (I think she is over five foot tall, but not by a whole lot). She occasionally gets mistaken for a young man. She has pretty short hair. Today she walked into a hairdresser that advertised $12 haircuts for men with very little money in her pocket and asked for a boys haircut. The hairdresser gave her a haircut but charged her for a 'ladies' haircut. She didn't have the money, was told to use her credit card, and to add insult to injury was told the business charged a $2 fee for credit card payment.
In whose world is this OK? In whose world is it OK to charge my brother with his handsome, long, curly, difficult hair (and penis) one price but my friend with her handsome, short, straight, neat hair (and vagina) a higher price? It's not OK in my world!
The anti-discrimination board clearly states that:
Sex discrimination is against the law... ...when you get or try to get most types of goods or services – for example, from shops, banks, lawyers, government departments, the police, public transport, local councils, doctors, hospitals and other medical services, hotels, sporting venues and entertainment venues;
from the Anti-discrimination Board of NSW sex-discrimination fact sheetSo this behavior is not OK in NSW law, either.
(Here endeth my rant, but if this, or something like this, has happened to you and you want to make a complaint but need some not-a-lawyer support, let me know and I'll be so happy to help you out)