Before the rebellion in the garden of Eden, the nakedness of Adam and Eve was not seen as wrong, for they were husband and wife.(Gen 2:25) However, with their being a mutiny against God's sovereignty in the garden of Eden, this brought forth sin and changes.(sin is from the Hebrew word chattath that means to "miss", as in missing when shooting an arrow, missing the mark of perfect obedience to our Maker, Jehovah God)
After eating from the "tree of knowledge of good and bad" (that represented Jehovah's right to establish moral boundaries for man as his creation and to test Adam and Eve's loyalty), suddenly both Adam and Eve became aware that they were naked.(Gen 3:7) Their consciences went into operation, causing them to feel guilt, and in which God asks Adam: "Who told you that you were naked ?"(Gen 3:10, 11)
But now the perfect humans that God had made were now defiled, sinners, imperfect, violators of Jehovah's command.(Gen 2:17) Their guilt-stricken consciences made them aware that they were naked, so that they immediately sought to cover their sexual organs.(Gen 3:6, 7)
This showed that their consciences were functioning as designed, to warn us when we are about to do wrong or prick us when we have crossed a moral boundary.(in their case, they recognized their nakedness only "after the fact", after they sinned, for nakedness up till then was not wrong)
In putting Adam and Eve outside the garden, "Jehovah God made long garments from skins for Adam and for his wife, to clothe them."(Gen 3:21) In imperfection, sexual desire can run amok. Having been designed with a conscience (that literally means co-knowledge, or knowledge with oneself), and when influenced by Bible principles, it jabs us when we reach a threshold point, such as how much we show of our bodies.
At Micah 6, it says: "He (Jehovah) has told you, O man, what is good. And what is Jehovah requiring of you ? Only to exercise justice, to cherish loyalty, and to walk in modesty (Hebrew tsana) with your God !"(Micah 6:8) What does the word modesty mean ? To know our limitations, from the authority we may or may not have to the clothes we wear.
One definition of modesty is defined as "sexual reserve".(Microsoft 2005 Reference Library) Hence, combined with how God covered Adam and Eve with "long garments", is an indicator of how we are to clothe ourselves. Being as the breasts of a woman are "connected" with her sexual organ, then modesty calls for these being fully covered, so as not to entice men.(see Prov 5:19 that says that a husband is "intoxicated" by his wife's breasts)
Also Proverbs 11:2 says that "when presumptuousness comes, dishonor will follow, but wisdom is with the modest (Hebrew tsana) ones." Those who reveal themselves so to be "sexy" are presumptuous, but those who are modest in their dress are seen as having godly wisdom.
We are living in an era of time, called "the last days" (or "conclusion of a system of things", Matt 24:3), whereby both men and women are "headstrong, puffed up with pride, lovers of pleasure rather than lovers of God."(2 Tim 3:4) These have no moral restraints, but whatever "feels good, then do it".
Modesty is a word that has been cast aside, and up to the "end" of this "world" in the near future, it will be seen as an obstacle to "fun" by many.(see Matt 24:12 in which Jesus says that during "the conclusion of the system of things", that "the love of the greater number will grow cold.")