Talk:Weiss Schnee/@comment-3257939-20151005115922/@comment-4010415-20151006204650

Bras are meant to support breasts (and keep your nipples from showing through your shirt). A bra that's too big doesn't offer the right amount of support, and the cup can end up with empty space in it rather than really cupping the breasts. Too small, and it can squish the breasts, they can "overflow," and if the cups are waaaay too small, they can have a hard time holding the breasts in.

Though, to be honest, I've heard that C and under don't really need a bra for support. But there's still that thing I mentioned about keeping the nipples hidden.