Rachel and I were talking about this topic tonight, and here is our conclusion.
Immodesty is a temptation for women. Women need to resist the temptation to be immodest. They often think they are doing the male population a big service by not wearing that tight t-shirt, but the truth is, they want to wear it (and they want to talk about how they almost wore it but decided it would stumble the whole world if they did). Why? Because it will provoke envy among the women and provoke lust among the men. Women are tempted to be immodest, and they have to learn to resist the temptation themselves.
Modesty is not really about the guys, though I’m sure they appreciate it (some of them anyway). In fact, when you think about it, it really isn’t about them at all. Modesty is about the women. God wants us to be modest because it pleases Him and is good for our own souls.