What is it you like about the bra?
First off, I'd just like to say I am not a cross-dresser or anything. I like them as they are nice garments. Tactile materials and nice colours. Yeah, I guess there is a small amount of sexual fantasy - especially the 38JJ ha ha. But mostly it isn't about that.
I've had this discussion with female friend a number of times - and for me, it is that women have much more variety of clothes and styles. Look at any office, the guys wear suits and the ladies wear all sorts of styles and designs. As a man I feel a bit hard-done-by to be honest.
So although I don't cross-dress, if society allowed me to dress differently, I may well feel like doing that if the mood took me.