Modesty is not so much about clothes as it is about intent. It’s not so much what is worn, but how it is worn and the attitude that goes along with the presentation.
Don’t get me wrong. Certain clothing is objectively immodest. But for a woman to be immodest, she must be at risk of looking provocative. So a woman who is not trying to be immodest, or believes that, in fact, she is not being immodest, can still be objectively immodest by the fact that certain clothing she is wearing presents her in a way that compels being noticed by men.
To lust after a woman is to desire her in a sexual, physical and inappropriate way. A man desiring to have sex with a woman he is simply looking at is, by definition, lust. It is a man’s responsibility to practice self-control and self-mastery in order to not be inclined to lust after a woman. Plenty of modestly dressed women are beautiful and desirable looking. A woman cannot be made to take full blame for a man desiring her.
Christian men are legitimately frustrated that they are exposed to women who are dressed provocatively. Certain clothes on certain body types are going to be eye catching. Women know this, and sorry to say, they have enough vanity at times to enjoy it. It’s natural for a woman to want to be noticed and considered beautiful. I highly doubt, however, that you can find a Christian woman who would say she is happy if a man lusts after her.
The dilemma is you have Christian women who live in a culture where they can get away with dressing all kinds of ways without knowing a fine line between modesty and immodesty, and men who have the problem you expressed; namely of loving it and hating it at the same time. How can they not love seeing a girl dressed very noticeably? (I refuse to use the word “hot,” but I’m sure many of you are thinking that is what I mean, and rightly so.) But at the same time, he feels bad for being so seemingly shallow (or maybe he doesn’t think of that part at all).
The truth is, the clothes are not the only contributor, nor the worst of it. Also contributing to the outward appearance is makeup and hair style. And the worst of it is the attitude behind the appearance.