I used to wear my wifes undies, and when she found out she divorsed me. It might be that he just likes wearing girls undies, there is no harm in that.
Does he shave his legs, butt and pubic area?
he's not that uncommon; you see i've a bud that was an escorte and she's told me many stories such as yours.
Thongs and stockings are an awesome combo.
I think you should cater to it and let him carry it as far as he wants. Wear a pair for about a week and let him wear the dirty ones and take a picture of him in them.
It's a common fetish. Encourage it and enjoy the benefits by shopping together.
