That's is b/c once a guy wears girls clothe it stays in his mind. It never goes away and he will always think about it forever. So my advice is to not fight it, and enjoy the gift you have as much as you can.
It's better than a vat of acid, or magma, or a pile of fish guts I suppose.
I guess the same reason I end up putting on a t shirt and jeans and rolling around in the mud. Because it appeals to me.