>>33490162 (OP)For most mammals, large mammary organs are a turn-off for males because they indicate pregnancy and therefore infertility. Humans have permanent breasts unlike almost all other mammals (so they're not a clear fertility signal), and for some reason men find them arousing. Obviously we have much more complex and social-oriented reproductive behaviors, and while the more permanent signs of fertility (and genetic health) are still signals of 'attractiveness' in humans, transient ones like breasts seem to have become so irrelevant that they've gone in the opposite direction.
Anyways, I don't know. Personally I like proportionality, which makes sense biologically. Breasts that are small proportionally to the woman make her seem physically immature or sickly, so there has to be something there, at least.