In an ideal world I am totally on board with people wearing what the hell they want. Clothes are clothes, they don’t alter our biology and wearing a skirt when you have a penis doesn’t mean you should take hormones and have your penis chopped off.
Unfortunately this is not the world we live in. The whole of our society has deeply ingrained ideas about what certain clothes mean. For that reason it’s VERY rare for a man to be wearing a skirt and heel because he genuinely just likes them as clothes in the same way he has a favourite pair of jeans or a t shirt. Men wearing skirts and heels is often related to a fetish and I have no issue with consenting adults doing what they like in private but I don’t think it’s necessary to be faced with people’s sexual fetishes on the bus or at work.
So I’m a bit torn- if it genuinely really is just that he wants to wear that or is making a point that biological sex is about chromosomes, not clothing or behaviour, then good on him, we need more of that. If he’s just involving the world in his fetish, then that’s not ok.