Thank you so much for your kind words. You sound such an incredibly supportive parent and your son is very lucky.
Your question is a really good one and has made me think. At a young age I knew that certain colours, materials and activities were considered girls and that I wasn’t supposed to like them. In my teens I soon learnt that it could be dangerous to have a feminine look. Throughout my life I have always worn colourful and untypical make clothes.
I think the difference now is my realisation that I am liking certain clothes or colours because they are gendered female. You and your son are both right that clothes gendering are merely social constructs and many clothes can be androgynous. Often however I am aware that I feel more comfortable and at peace if I am wearing women’s clothing rather than mens, even if others are not aware that what I am wearing has been brought from the women’s section.
I hope this helps in some way.