I've flown almost every week for several years in drab. I've worn underwire bras and often forms on most every flight and seldom set off the alarms. None of which were because of my bra, but because I forgot which belt I was wearing, etc. I've been wanded and simply said my bra or that's the underwires. As I usually wear women's shirts and leave the second button undone. More than once I have simply pealed back the top so that they can see the bra's lace, they smile and I go on. TSA could care less.
The new system will show clothing lines. So it won't matter, the underwire will show along with the band, the cups, your cute thong, etc. Why worry, they are not going to stamp you with some symbol for crossdressing. Personally I don't care what they see, just nail the guy with the bomb. I don't want to skydive from 30,000 ft.
