Both and neither. It so much depends on the circumstance and the woman wearing or not wearing one. Personally I like girls and women without a bra more than those with one but sometimes you just gotta say, "Ya know girl you forgot to put on your bra".
@hippyjoe1955: Haha. I know what you mean. I usually don't care, its a personal choice. It also really depends on what you are wearing when you choose not to wear a bra.
