Nobody cares about that at TSA checkpoints. They're looking for dangerous items..not clothing. There's no reason to check anything. If you were going through customs and someone opened your bag they may inquire about that (thinking about the movie "Blow" where he was carrying cocaine hidden in a compartment in his suitcase which was full of women's clothing..got a funny look and question from the customs agent but was allowed to continue). But even if you were going through customs there would be no reason to worry.. clothing of the opposite sex isn't on anyone's radar as being an issue. I wouldn't recommend heading to Saudi Arabia with it though..