I'm guessing it's because they're sex organs and things happen to them when they get aroused. LIke if some guy touches your knee, nothing happens, but if a guy touches your boobs then...thing happen hahaha. Also they're a rare sight (minus porn magazines, and movies.) No matter how loose fit clothing or tight clothing a girl wears, her boobs are always covered. Even in bikini's. They can be as skimpy as hell but their boobs are always partially covered I think guys like them so much because for a long time they;re forbidden from their sight and touch until they can get close emotionally enough with a girl to gain trust and to sleep with her and fool around.
